From 85b723c4e6c88fc5d7e1e3f6b3c86711144882b5 Mon Sep 17 00:00:00 2001 From: Santiago Pastorino Date: Fri, 3 Dec 2021 10:11:21 -0300 Subject: [PATCH] Revert "Auto merge of #91354 - fee1-dead:const_env, r=spastorino" This reverts commit 18bb8c61a975fff6424cda831ace5b0404277145, reversing changes made to d9baa361902b172be716f96619b909f340802dea. --- compiler/rustc_borrowck/src/type_check/mod.rs | 2 +- .../src/const_eval/eval_queries.rs | 3 - .../src/interpret/eval_context.rs | 1 - .../src/transform/check_consts/check.rs | 3 +- .../src/transform/check_consts/qualifs.rs | 3 +- compiler/rustc_hir/src/hir.rs | 25 ++ compiler/rustc_infer/src/traits/engine.rs | 20 +- compiler/rustc_infer/src/traits/mod.rs | 10 - compiler/rustc_infer/src/traits/util.rs | 10 +- compiler/rustc_middle/src/hir/map/mod.rs | 3 +- .../rustc_middle/src/mir/interpret/queries.rs | 2 - compiler/rustc_middle/src/traits/select.rs | 10 +- compiler/rustc_middle/src/traits/util.rs | 4 +- compiler/rustc_middle/src/ty/mod.rs | 130 ++++------ compiler/rustc_middle/src/ty/relate.rs | 13 + .../rustc_middle/src/ty/structural_impls.rs | 2 +- compiler/rustc_middle/src/ty/sty.rs | 4 +- .../rustc_trait_selection/src/autoderef.rs | 2 +- compiler/rustc_trait_selection/src/infer.rs | 1 + .../src/traits/auto_trait.rs | 7 +- .../src/traits/error_reporting/mod.rs | 2 +- .../src/traits/error_reporting/suggestions.rs | 2 +- .../src/traits/fulfill.rs | 39 ++- .../rustc_trait_selection/src/traits/mod.rs | 36 +-- .../src/traits/object_safety.rs | 8 +- .../src/traits/project.rs | 2 +- .../src/traits/select/candidate_assembly.rs | 14 +- .../src/traits/select/confirmation.rs | 16 +- .../src/traits/select/mod.rs | 236 +++++++++++------- .../src/traits/specialize/mod.rs | 6 +- .../rustc_trait_selection/src/traits/util.rs | 10 +- .../rustc_trait_selection/src/traits/wf.rs | 7 +- compiler/rustc_ty_utils/src/ty.rs | 85 +------ compiler/rustc_typeck/src/astconv/mod.rs | 2 +- compiler/rustc_typeck/src/bounds.rs | 2 +- .../rustc_typeck/src/check/compare_method.rs | 31 ++- .../rustc_typeck/src/check/fn_ctxt/_impl.rs | 10 +- compiler/rustc_typeck/src/check/inherited.rs | 14 ++ compiler/rustc_typeck/src/check/method/mod.rs | 2 +- .../rustc_typeck/src/check/method/probe.rs | 2 +- .../rustc_typeck/src/check/method/suggest.rs | 2 +- compiler/rustc_typeck/src/check/wfcheck.rs | 1 + compiler/rustc_typeck/src/collect.rs | 2 +- src/librustdoc/clean/blanket_impl.rs | 5 +- src/test/ui/infinite/infinite-struct.stderr | 2 +- .../infinite-tag-type-recursion.stderr | 2 +- .../rfc-2632-const-trait-impl/assoc-type.rs | 1 + .../assoc-type.stderr | 4 +- .../clippy_lints/src/future_not_send.rs | 4 +- 49 files changed, 428 insertions(+), 376 deletions(-) diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs index d90154f164386..da26d9c7b8779 100644 --- a/compiler/rustc_borrowck/src/type_check/mod.rs +++ b/compiler/rustc_borrowck/src/type_check/mod.rs @@ -31,7 +31,7 @@ use rustc_middle::ty::fold::TypeFoldable; use rustc_middle::ty::subst::{GenericArgKind, SubstsRef, UserSubsts}; use rustc_middle::ty::{ self, CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations, OpaqueTypeKey, RegionVid, - ToPredicate, Ty, TyCtxt, UserType, UserTypeAnnotationIndex, + ToPredicate, Ty, TyCtxt, UserType, UserTypeAnnotationIndex, WithConstness, }; use rustc_span::def_id::CRATE_DEF_ID; use rustc_span::{Span, DUMMY_SP}; diff --git a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs index c5412affafe23..6d3a89c0a8a5b 100644 --- a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs +++ b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs @@ -7,7 +7,6 @@ use crate::interpret::{ }; use rustc_errors::ErrorReported; -use rustc_hir as hir; use rustc_hir::def::DefKind; use rustc_middle::mir; use rustc_middle::mir::interpret::ErrorHandled; @@ -216,7 +215,6 @@ pub fn eval_to_const_value_raw_provider<'tcx>( tcx: TyCtxt<'tcx>, key: ty::ParamEnvAnd<'tcx, GlobalId<'tcx>>, ) -> ::rustc_middle::mir::interpret::EvalToConstValueResult<'tcx> { - assert!(key.param_env.constness() == hir::Constness::Const); // see comment in eval_to_allocation_raw_provider for what we're doing here if key.param_env.reveal() == Reveal::All { let mut key = key; @@ -251,7 +249,6 @@ pub fn eval_to_allocation_raw_provider<'tcx>( tcx: TyCtxt<'tcx>, key: ty::ParamEnvAnd<'tcx, GlobalId<'tcx>>, ) -> ::rustc_middle::mir::interpret::EvalToAllocationRawResult<'tcx> { - assert!(key.param_env.constness() == hir::Constness::Const); // Because the constant is computed twice (once per value of `Reveal`), we are at risk of // reporting the same error twice here. To resolve this, we check whether we can evaluate the // constant in the more restrictive `Reveal::UserFacing`, which most likely already was diff --git a/compiler/rustc_const_eval/src/interpret/eval_context.rs b/compiler/rustc_const_eval/src/interpret/eval_context.rs index 6206deb211533..cf084faade8cc 100644 --- a/compiler/rustc_const_eval/src/interpret/eval_context.rs +++ b/compiler/rustc_const_eval/src/interpret/eval_context.rs @@ -918,7 +918,6 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { } else { self.param_env }; - let param_env = param_env.with_const(); let val = self.tcx.eval_to_allocation_raw(param_env.and(gid))?; self.raw_const_to_mplace(val) } diff --git a/compiler/rustc_const_eval/src/transform/check_consts/check.rs b/compiler/rustc_const_eval/src/transform/check_consts/check.rs index f9e65ea907564..274665ccd9836 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/check.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/check.rs @@ -817,7 +817,8 @@ impl Visitor<'tcx> for Checker<'mir, 'tcx> { ); let implsrc = tcx.infer_ctxt().enter(|infcx| { - let mut selcx = SelectionContext::new(&infcx); + let mut selcx = + SelectionContext::with_constness(&infcx, hir::Constness::Const); selcx.select(&obligation) }); diff --git a/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs b/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs index 43612292f5283..abc5a3c6a5206 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs @@ -3,6 +3,7 @@ //! See the `Qualif` trait for more info. use rustc_errors::ErrorReported; +use rustc_hir as hir; use rustc_infer::infer::TyCtxtInferExt; use rustc_middle::mir::*; use rustc_middle::ty::{self, subst::SubstsRef, AdtDef, Ty}; @@ -166,7 +167,7 @@ impl Qualif for NeedsNonConstDrop { ); let implsrc = cx.tcx.infer_ctxt().enter(|infcx| { - let mut selcx = SelectionContext::new(&infcx); + let mut selcx = SelectionContext::with_constness(&infcx, hir::Constness::Const); selcx.select(&obligation) }); !matches!( diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs index 61a96564a4c78..2466e69f83646 100644 --- a/compiler/rustc_hir/src/hir.rs +++ b/compiler/rustc_hir/src/hir.rs @@ -3230,6 +3230,31 @@ impl<'hir> Node<'hir> { } } + /// Returns `Constness::Const` when this node is a const fn/impl/item. + pub fn constness_for_typeck(&self) -> Constness { + match self { + Node::Item(Item { + kind: ItemKind::Fn(FnSig { header: FnHeader { constness, .. }, .. }, ..), + .. + }) + | Node::TraitItem(TraitItem { + kind: TraitItemKind::Fn(FnSig { header: FnHeader { constness, .. }, .. }, ..), + .. + }) + | Node::ImplItem(ImplItem { + kind: ImplItemKind::Fn(FnSig { header: FnHeader { constness, .. }, .. }, ..), + .. + }) + | Node::Item(Item { kind: ItemKind::Impl(Impl { constness, .. }), .. }) => *constness, + + Node::Item(Item { kind: ItemKind::Const(..), .. }) + | Node::TraitItem(TraitItem { kind: TraitItemKind::Const(..), .. }) + | Node::ImplItem(ImplItem { kind: ImplItemKind::Const(..), .. }) => Constness::Const, + + _ => Constness::NotConst, + } + } + pub fn as_owner(self) -> Option> { match self { Node::Item(i) => Some(OwnerNode::Item(i)), diff --git a/compiler/rustc_infer/src/traits/engine.rs b/compiler/rustc_infer/src/traits/engine.rs index 822f2365e023f..152a395c871be 100644 --- a/compiler/rustc_infer/src/traits/engine.rs +++ b/compiler/rustc_infer/src/traits/engine.rs @@ -1,8 +1,9 @@ use crate::infer::InferCtxt; use crate::traits::Obligation; use rustc_data_structures::fx::FxHashMap; +use rustc_hir as hir; use rustc_hir::def_id::DefId; -use rustc_middle::ty::{self, ToPredicate, Ty}; +use rustc_middle::ty::{self, ToPredicate, Ty, WithConstness}; use super::FulfillmentError; use super::{ObligationCause, PredicateObligation}; @@ -47,9 +48,26 @@ pub trait TraitEngine<'tcx>: 'tcx { fn select_all_or_error(&mut self, infcx: &InferCtxt<'_, 'tcx>) -> Vec>; + fn select_all_with_constness_or_error( + &mut self, + infcx: &InferCtxt<'_, 'tcx>, + _constness: hir::Constness, + ) -> Vec> { + self.select_all_or_error(infcx) + } + fn select_where_possible(&mut self, infcx: &InferCtxt<'_, 'tcx>) -> Vec>; + // FIXME(fee1-dead) this should not provide a default body for chalk as chalk should be updated + fn select_with_constness_where_possible( + &mut self, + infcx: &InferCtxt<'_, 'tcx>, + _constness: hir::Constness, + ) -> Vec> { + self.select_where_possible(infcx) + } + fn pending_obligations(&self) -> Vec>; fn relationships(&mut self) -> &mut FxHashMap; diff --git a/compiler/rustc_infer/src/traits/mod.rs b/compiler/rustc_infer/src/traits/mod.rs index 7e30f859dae4e..e8622b3c819d2 100644 --- a/compiler/rustc_infer/src/traits/mod.rs +++ b/compiler/rustc_infer/src/traits/mod.rs @@ -69,16 +69,6 @@ impl PredicateObligation<'tcx> { } } -impl TraitObligation<'tcx> { - /// Returns `true` if the trait predicate is considered `const` in its ParamEnv. - pub fn is_const(&self) -> bool { - match (self.predicate.skip_binder().constness, self.param_env.constness()) { - (ty::BoundConstness::ConstIfConst, hir::Constness::Const) => true, - _ => false, - } - } -} - // `PredicateObligation` is used a lot. Make sure it doesn't unintentionally get bigger. #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))] static_assert_size!(PredicateObligation<'_>, 32); diff --git a/compiler/rustc_infer/src/traits/util.rs b/compiler/rustc_infer/src/traits/util.rs index 61588147364a9..92f74af4eb3eb 100644 --- a/compiler/rustc_infer/src/traits/util.rs +++ b/compiler/rustc_infer/src/traits/util.rs @@ -3,7 +3,7 @@ use smallvec::smallvec; use crate::infer::outlives::components::{push_outlives_components, Component}; use crate::traits::{Obligation, ObligationCause, PredicateObligation}; use rustc_data_structures::fx::{FxHashSet, FxIndexSet}; -use rustc_middle::ty::{self, ToPredicate, TyCtxt}; +use rustc_middle::ty::{self, ToPredicate, TyCtxt, WithConstness}; use rustc_span::symbol::Ident; use rustc_span::Span; @@ -328,8 +328,8 @@ pub fn transitive_bounds_that_define_assoc_type<'tcx>( )); for (super_predicate, _) in super_predicates.predicates { let subst_predicate = super_predicate.subst_supertrait(tcx, &trait_ref); - if let Some(binder) = subst_predicate.to_opt_poly_trait_pred() { - stack.push(binder.map_bound(|t| t.trait_ref)); + if let Some(binder) = subst_predicate.to_opt_poly_trait_ref() { + stack.push(binder.value); } } @@ -362,8 +362,8 @@ impl<'tcx, I: Iterator>> Iterator for FilterToT fn next(&mut self) -> Option> { while let Some(obligation) = self.base_iterator.next() { - if let Some(data) = obligation.predicate.to_opt_poly_trait_pred() { - return Some(data.map_bound(|t| t.trait_ref)); + if let Some(data) = obligation.predicate.to_opt_poly_trait_ref() { + return Some(data.value); } } None diff --git a/compiler/rustc_middle/src/hir/map/mod.rs b/compiler/rustc_middle/src/hir/map/mod.rs index 394a1fc227095..5c4c2eee21fc1 100644 --- a/compiler/rustc_middle/src/hir/map/mod.rs +++ b/compiler/rustc_middle/src/hir/map/mod.rs @@ -474,8 +474,7 @@ impl<'hir> Map<'hir> { /// Panics if `LocalDefId` does not have an associated body. /// /// This should only be used for determining the context of a body, a return - /// value of `Some` does not always suggest that the owner of the body is `const`, - /// just that it has to be checked as if it were. + /// value of `Some` does not always suggest that the owner of the body is `const`. pub fn body_const_context(&self, did: LocalDefId) -> Option { let hir_id = self.local_def_id_to_hir_id(did); let ccx = match self.body_owner_kind(hir_id) { diff --git a/compiler/rustc_middle/src/mir/interpret/queries.rs b/compiler/rustc_middle/src/mir/interpret/queries.rs index f983185563315..c63613ae3af29 100644 --- a/compiler/rustc_middle/src/mir/interpret/queries.rs +++ b/compiler/rustc_middle/src/mir/interpret/queries.rs @@ -64,7 +64,6 @@ impl<'tcx> TyCtxt<'tcx> { cid: GlobalId<'tcx>, span: Option, ) -> EvalToConstValueResult<'tcx> { - let param_env = param_env.with_const(); // Const-eval shouldn't depend on lifetimes at all, so we can erase them, which should // improve caching of queries. let inputs = self.erase_regions(param_env.and(cid)); @@ -93,7 +92,6 @@ impl<'tcx> TyCtxt<'tcx> { gid: GlobalId<'tcx>, param_env: ty::ParamEnv<'tcx>, ) -> Result<&'tcx mir::Allocation, ErrorHandled> { - let param_env = param_env.with_const(); trace!("eval_to_allocation: Need to compute {:?}", gid); let raw_const = self.eval_to_allocation_raw(param_env.and(gid))?; Ok(self.global_alloc(raw_const.alloc_id).unwrap_memory()) diff --git a/compiler/rustc_middle/src/traits/select.rs b/compiler/rustc_middle/src/traits/select.rs index 71ee00c602a3d..560660517f34b 100644 --- a/compiler/rustc_middle/src/traits/select.rs +++ b/compiler/rustc_middle/src/traits/select.rs @@ -12,12 +12,14 @@ use rustc_hir::def_id::DefId; use rustc_query_system::cache::Cache; pub type SelectionCache<'tcx> = Cache< - ty::ParamEnvAnd<'tcx, ty::TraitPredicate<'tcx>>, + (ty::ConstnessAnd>>, ty::ImplPolarity), SelectionResult<'tcx, SelectionCandidate<'tcx>>, >; -pub type EvaluationCache<'tcx> = - Cache>, EvaluationResult>; +pub type EvaluationCache<'tcx> = Cache< + (ty::ParamEnvAnd<'tcx, ty::ConstnessAnd>>, ty::ImplPolarity), + EvaluationResult, +>; /// The selection process begins by considering all impls, where /// clauses, and so forth that might resolve an obligation. Sometimes @@ -101,7 +103,7 @@ pub enum SelectionCandidate<'tcx> { /// `false` if there are no *further* obligations. has_nested: bool, }, - ParamCandidate(ty::PolyTraitPredicate<'tcx>), + ParamCandidate((ty::ConstnessAnd>, ty::ImplPolarity)), ImplCandidate(DefId), AutoImplCandidate(DefId), diff --git a/compiler/rustc_middle/src/traits/util.rs b/compiler/rustc_middle/src/traits/util.rs index 815f4824bc134..3490c6881704a 100644 --- a/compiler/rustc_middle/src/traits/util.rs +++ b/compiler/rustc_middle/src/traits/util.rs @@ -26,9 +26,9 @@ impl<'tcx> Elaborator<'tcx> { .predicates .into_iter() .flat_map(|(pred, _)| { - pred.subst_supertrait(self.tcx, &trait_ref).to_opt_poly_trait_pred() + pred.subst_supertrait(self.tcx, &trait_ref).to_opt_poly_trait_ref() }) - .map(|t| t.map_bound(|pred| pred.trait_ref)) + .map(|t| t.value) .filter(|supertrait_ref| self.visited.insert(*supertrait_ref)); self.stack.extend(supertrait_refs); diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs index 584303413fb87..5070e1565b3d4 100644 --- a/compiler/rustc_middle/src/ty/mod.rs +++ b/compiler/rustc_middle/src/ty/mod.rs @@ -230,19 +230,6 @@ pub enum BoundConstness { ConstIfConst, } -impl BoundConstness { - /// Reduce `self` and `constness` to two possible combined states instead of four. - pub fn and(&mut self, constness: hir::Constness) -> hir::Constness { - match (constness, self) { - (hir::Constness::Const, BoundConstness::ConstIfConst) => hir::Constness::Const, - (_, this) => { - *this = BoundConstness::NotConst; - hir::Constness::NotConst - } - } - } -} - impl fmt::Display for BoundConstness { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { match self { @@ -859,6 +846,20 @@ impl ToPredicate<'tcx> for Binder<'tcx, PredicateKind<'tcx>> { } } +impl<'tcx> ToPredicate<'tcx> for ConstnessAnd> { + fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { + self.value + .map_bound(|trait_ref| { + PredicateKind::Trait(ty::TraitPredicate { + trait_ref, + constness: self.constness, + polarity: ty::ImplPolarity::Positive, + }) + }) + .to_predicate(tcx) + } +} + impl<'tcx> ToPredicate<'tcx> for PolyTraitPredicate<'tcx> { fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { self.map_bound(PredicateKind::Trait).to_predicate(tcx) @@ -884,10 +885,12 @@ impl<'tcx> ToPredicate<'tcx> for PolyProjectionPredicate<'tcx> { } impl<'tcx> Predicate<'tcx> { - pub fn to_opt_poly_trait_pred(self) -> Option> { + pub fn to_opt_poly_trait_ref(self) -> Option>> { let predicate = self.kind(); match predicate.skip_binder() { - PredicateKind::Trait(t) => Some(predicate.rebind(t)), + PredicateKind::Trait(t) => { + Some(ConstnessAnd { constness: t.constness, value: predicate.rebind(t.trait_ref) }) + } PredicateKind::Projection(..) | PredicateKind::Subtype(..) | PredicateKind::Coerce(..) @@ -1218,33 +1221,23 @@ pub struct ParamEnv<'tcx> { /// want `Reveal::All`. /// /// Note: This is packed, use the reveal() method to access it. - packed: CopyTaggedPtr<&'tcx List>, ParamTag, true>, + packed: CopyTaggedPtr<&'tcx List>, traits::Reveal, true>, } -#[derive(Copy, Clone)] -struct ParamTag { - reveal: traits::Reveal, - constness: hir::Constness, -} - -unsafe impl rustc_data_structures::tagged_ptr::Tag for ParamTag { - const BITS: usize = 2; +unsafe impl rustc_data_structures::tagged_ptr::Tag for traits::Reveal { + const BITS: usize = 1; #[inline] fn into_usize(self) -> usize { match self { - Self { reveal: traits::Reveal::UserFacing, constness: hir::Constness::NotConst } => 0, - Self { reveal: traits::Reveal::All, constness: hir::Constness::NotConst } => 1, - Self { reveal: traits::Reveal::UserFacing, constness: hir::Constness::Const } => 2, - Self { reveal: traits::Reveal::All, constness: hir::Constness::Const } => 3, + traits::Reveal::UserFacing => 0, + traits::Reveal::All => 1, } } #[inline] unsafe fn from_usize(ptr: usize) -> Self { match ptr { - 0 => Self { reveal: traits::Reveal::UserFacing, constness: hir::Constness::NotConst }, - 1 => Self { reveal: traits::Reveal::All, constness: hir::Constness::NotConst }, - 2 => Self { reveal: traits::Reveal::UserFacing, constness: hir::Constness::Const }, - 3 => Self { reveal: traits::Reveal::All, constness: hir::Constness::Const }, + 0 => traits::Reveal::UserFacing, + 1 => traits::Reveal::All, _ => std::hint::unreachable_unchecked(), } } @@ -1255,7 +1248,6 @@ impl<'tcx> fmt::Debug for ParamEnv<'tcx> { f.debug_struct("ParamEnv") .field("caller_bounds", &self.caller_bounds()) .field("reveal", &self.reveal()) - .field("constness", &self.constness()) .finish() } } @@ -1264,7 +1256,6 @@ impl<'a, 'tcx> HashStable> for ParamEnv<'tcx> { fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) { self.caller_bounds().hash_stable(hcx, hasher); self.reveal().hash_stable(hcx, hasher); - self.constness().hash_stable(hcx, hasher); } } @@ -1276,14 +1267,12 @@ impl<'tcx> TypeFoldable<'tcx> for ParamEnv<'tcx> { Ok(ParamEnv::new( self.caller_bounds().try_fold_with(folder)?, self.reveal().try_fold_with(folder)?, - self.constness().try_fold_with(folder)?, )) } fn super_visit_with>(&self, visitor: &mut V) -> ControlFlow { self.caller_bounds().visit_with(visitor)?; - self.reveal().visit_with(visitor)?; - self.constness().visit_with(visitor) + self.reveal().visit_with(visitor) } } @@ -1294,7 +1283,7 @@ impl<'tcx> ParamEnv<'tcx> { /// type-checking. #[inline] pub fn empty() -> Self { - Self::new(List::empty(), Reveal::UserFacing, hir::Constness::NotConst) + Self::new(List::empty(), Reveal::UserFacing) } #[inline] @@ -1304,12 +1293,7 @@ impl<'tcx> ParamEnv<'tcx> { #[inline] pub fn reveal(self) -> traits::Reveal { - self.packed.tag().reveal - } - - #[inline] - pub fn constness(self) -> hir::Constness { - self.packed.tag().constness + self.packed.tag() } /// Construct a trait environment with no where-clauses in scope @@ -1321,31 +1305,17 @@ impl<'tcx> ParamEnv<'tcx> { /// or invoke `param_env.with_reveal_all()`. #[inline] pub fn reveal_all() -> Self { - Self::new(List::empty(), Reveal::All, hir::Constness::NotConst) + Self::new(List::empty(), Reveal::All) } /// Construct a trait environment with the given set of predicates. #[inline] - pub fn new( - caller_bounds: &'tcx List>, - reveal: Reveal, - constness: hir::Constness, - ) -> Self { - ty::ParamEnv { packed: CopyTaggedPtr::new(caller_bounds, ParamTag { reveal, constness }) } + pub fn new(caller_bounds: &'tcx List>, reveal: Reveal) -> Self { + ty::ParamEnv { packed: CopyTaggedPtr::new(caller_bounds, reveal) } } pub fn with_user_facing(mut self) -> Self { - self.packed.set_tag(ParamTag { reveal: Reveal::UserFacing, ..self.packed.tag() }); - self - } - - pub fn with_constness(mut self, constness: hir::Constness) -> Self { - self.packed.set_tag(ParamTag { constness, ..self.packed.tag() }); - self - } - - pub fn with_const(mut self) -> Self { - self.packed.set_tag(ParamTag { constness: hir::Constness::Const, ..self.packed.tag() }); + self.packed.set_tag(Reveal::UserFacing); self } @@ -1359,21 +1329,17 @@ impl<'tcx> ParamEnv<'tcx> { /// will be normalized to their underlying types. /// See PR #65989 and issue #65918 for more details pub fn with_reveal_all_normalized(self, tcx: TyCtxt<'tcx>) -> Self { - if self.packed.tag().reveal == traits::Reveal::All { + if self.packed.tag() == traits::Reveal::All { return self; } - ParamEnv::new( - tcx.normalize_opaque_types(self.caller_bounds()), - Reveal::All, - self.constness(), - ) + ParamEnv::new(tcx.normalize_opaque_types(self.caller_bounds()), Reveal::All) } /// Returns this same environment but with no caller bounds. #[inline] pub fn without_caller_bounds(self) -> Self { - Self::new(List::empty(), self.reveal(), self.constness()) + Self::new(List::empty(), self.reveal()) } /// Creates a suitable environment in which to perform trait @@ -1403,23 +1369,33 @@ impl<'tcx> ParamEnv<'tcx> { } } +#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TypeFoldable)] +pub struct ConstnessAnd { + pub constness: BoundConstness, + pub value: T, +} + // FIXME(ecstaticmorse): Audit all occurrences of `without_const().to_predicate(tcx)` to ensure that // the constness of trait bounds is being propagated correctly. -impl PolyTraitRef<'tcx> { +pub trait WithConstness: Sized { #[inline] - pub fn with_constness(self, constness: BoundConstness) -> PolyTraitPredicate<'tcx> { - self.map_bound(|trait_ref| ty::TraitPredicate { - trait_ref, - constness, - polarity: ty::ImplPolarity::Positive, - }) + fn with_constness(self, constness: BoundConstness) -> ConstnessAnd { + ConstnessAnd { constness, value: self } + } + + #[inline] + fn with_const_if_const(self) -> ConstnessAnd { + self.with_constness(BoundConstness::ConstIfConst) } + #[inline] - pub fn without_const(self) -> PolyTraitPredicate<'tcx> { + fn without_const(self) -> ConstnessAnd { self.with_constness(BoundConstness::NotConst) } } +impl WithConstness for T {} + #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TypeFoldable)] pub struct ParamEnvAnd<'tcx, T> { pub param_env: ParamEnv<'tcx>, diff --git a/compiler/rustc_middle/src/ty/relate.rs b/compiler/rustc_middle/src/ty/relate.rs index b6aadf27bb08b..c7d8bec506f6b 100644 --- a/compiler/rustc_middle/src/ty/relate.rs +++ b/compiler/rustc_middle/src/ty/relate.rs @@ -218,6 +218,19 @@ impl<'tcx> Relate<'tcx> for ty::BoundConstness { } } +impl<'tcx, T: Relate<'tcx>> Relate<'tcx> for ty::ConstnessAnd { + fn relate>( + relation: &mut R, + a: ty::ConstnessAnd, + b: ty::ConstnessAnd, + ) -> RelateResult<'tcx, ty::ConstnessAnd> { + Ok(ty::ConstnessAnd { + constness: relation.relate(a.constness, b.constness)?, + value: relation.relate(a.value, b.value)?, + }) + } +} + impl<'tcx> Relate<'tcx> for ast::Unsafety { fn relate>( relation: &mut R, diff --git a/compiler/rustc_middle/src/ty/structural_impls.rs b/compiler/rustc_middle/src/ty/structural_impls.rs index 30ed008a5deeb..16a6c586358d9 100644 --- a/compiler/rustc_middle/src/ty/structural_impls.rs +++ b/compiler/rustc_middle/src/ty/structural_impls.rs @@ -480,7 +480,7 @@ impl<'a, 'tcx> Lift<'tcx> for ty::ParamEnv<'a> { type Lifted = ty::ParamEnv<'tcx>; fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option { tcx.lift(self.caller_bounds()) - .map(|caller_bounds| ty::ParamEnv::new(caller_bounds, self.reveal(), self.constness())) + .map(|caller_bounds| ty::ParamEnv::new(caller_bounds, self.reveal())) } } diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs index a80fe6a3362b4..6bd761d61e247 100644 --- a/compiler/rustc_middle/src/ty/sty.rs +++ b/compiler/rustc_middle/src/ty/sty.rs @@ -8,7 +8,9 @@ use crate::infer::canonical::Canonical; use crate::ty::fold::ValidateBoundVars; use crate::ty::subst::{GenericArg, InternalSubsts, Subst, SubstsRef}; use crate::ty::InferTy::{self, *}; -use crate::ty::{self, AdtDef, DefIdTree, Discr, Ty, TyCtxt, TypeFlags, TypeFoldable}; +use crate::ty::{ + self, AdtDef, DefIdTree, Discr, Ty, TyCtxt, TypeFlags, TypeFoldable, WithConstness, +}; use crate::ty::{DelaySpanBugEmitted, List, ParamEnv, TyS}; use polonius_engine::Atom; use rustc_data_structures::captures::Captures; diff --git a/compiler/rustc_trait_selection/src/autoderef.rs b/compiler/rustc_trait_selection/src/autoderef.rs index 46c74660f86a1..4c80483fc1f1e 100644 --- a/compiler/rustc_trait_selection/src/autoderef.rs +++ b/compiler/rustc_trait_selection/src/autoderef.rs @@ -3,7 +3,7 @@ use crate::traits::{self, TraitEngine}; use rustc_errors::struct_span_err; use rustc_hir as hir; use rustc_infer::infer::InferCtxt; -use rustc_middle::ty::{self, TraitRef, Ty, TyCtxt}; +use rustc_middle::ty::{self, TraitRef, Ty, TyCtxt, WithConstness}; use rustc_middle::ty::{ToPredicate, TypeFoldable}; use rustc_session::{DiagnosticMessageId, Limit}; use rustc_span::def_id::LOCAL_CRATE; diff --git a/compiler/rustc_trait_selection/src/infer.rs b/compiler/rustc_trait_selection/src/infer.rs index f135f0c1b13d2..70816b5722b2d 100644 --- a/compiler/rustc_trait_selection/src/infer.rs +++ b/compiler/rustc_trait_selection/src/infer.rs @@ -9,6 +9,7 @@ use rustc_middle::infer::canonical::{Canonical, CanonicalizedQueryResponse, Quer use rustc_middle::traits::query::Fallible; use rustc_middle::ty::subst::SubstsRef; use rustc_middle::ty::ToPredicate; +use rustc_middle::ty::WithConstness; use rustc_middle::ty::{self, Ty, TypeFoldable}; use rustc_span::{Span, DUMMY_SP}; diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs index 3642aebaec2fb..54f7b91080dd9 100644 --- a/compiler/rustc_trait_selection/src/traits/auto_trait.rs +++ b/compiler/rustc_trait_selection/src/traits/auto_trait.rs @@ -370,17 +370,12 @@ impl AutoTraitFinder<'tcx> { computed_preds.clone().chain(user_computed_preds.iter().cloned()), ) .map(|o| o.predicate); - new_env = ty::ParamEnv::new( - tcx.mk_predicates(normalized_preds), - param_env.reveal(), - param_env.constness(), - ); + new_env = ty::ParamEnv::new(tcx.mk_predicates(normalized_preds), param_env.reveal()); } let final_user_env = ty::ParamEnv::new( tcx.mk_predicates(user_computed_preds.into_iter()), user_env.reveal(), - user_env.constness(), ); debug!( "evaluate_nested_obligations(ty={:?}, trait_did={:?}): succeeded with '{:?}' \ diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs index ed56d4c28273f..d9f86fbc23b5d 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs @@ -24,7 +24,7 @@ use rustc_middle::ty::error::ExpectedFound; use rustc_middle::ty::fold::TypeFolder; use rustc_middle::ty::{ self, fast_reject, AdtKind, SubtypePredicate, ToPolyTraitRef, ToPredicate, Ty, TyCtxt, - TypeFoldable, + TypeFoldable, WithConstness, }; use rustc_session::DiagnosticMessageId; use rustc_span::symbol::{kw, sym}; diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs index af0a39b239fc4..a90140a9b50b9 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs @@ -21,7 +21,7 @@ use rustc_hir::lang_items::LangItem; use rustc_hir::{AsyncGeneratorKind, GeneratorKind, Node}; use rustc_middle::ty::{ self, suggest_arbitrary_trait_bound, suggest_constraining_type_param, AdtKind, DefIdTree, - Infer, InferTy, ToPredicate, Ty, TyCtxt, TypeFoldable, + Infer, InferTy, ToPredicate, Ty, TyCtxt, TypeFoldable, WithConstness, }; use rustc_middle::ty::{TypeAndMut, TypeckResults}; use rustc_session::Limit; diff --git a/compiler/rustc_trait_selection/src/traits/fulfill.rs b/compiler/rustc_trait_selection/src/traits/fulfill.rs index 8a60f9b8602f6..e121837c987ae 100644 --- a/compiler/rustc_trait_selection/src/traits/fulfill.rs +++ b/compiler/rustc_trait_selection/src/traits/fulfill.rs @@ -4,6 +4,7 @@ use rustc_data_structures::obligation_forest::ProcessResult; use rustc_data_structures::obligation_forest::{Error, ForestObligation, Outcome}; use rustc_data_structures::obligation_forest::{ObligationForest, ObligationProcessor}; use rustc_errors::ErrorReported; +use rustc_hir as hir; use rustc_infer::traits::{SelectionError, TraitEngine, TraitEngineExt as _, TraitObligation}; use rustc_middle::mir::interpret::ErrorHandled; use rustc_middle::thir::abstract_const::NotConstEvaluatable; @@ -230,6 +231,21 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> { self.predicates.to_errors(CodeAmbiguity).into_iter().map(to_fulfillment_error).collect() } + fn select_all_with_constness_or_error( + &mut self, + infcx: &InferCtxt<'_, 'tcx>, + constness: rustc_hir::Constness, + ) -> Vec> { + { + let errors = self.select_with_constness_where_possible(infcx, constness); + if !errors.is_empty() { + return errors; + } + } + + self.predicates.to_errors(CodeAmbiguity).into_iter().map(to_fulfillment_error).collect() + } + fn select_where_possible( &mut self, infcx: &InferCtxt<'_, 'tcx>, @@ -238,6 +254,15 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> { self.select(&mut selcx) } + fn select_with_constness_where_possible( + &mut self, + infcx: &InferCtxt<'_, 'tcx>, + constness: hir::Constness, + ) -> Vec> { + let mut selcx = SelectionContext::with_constness(infcx, constness); + self.select(&mut selcx) + } + fn pending_obligations(&self) -> Vec> { self.predicates.map_pending_obligations(|o| o.obligation.clone()) } @@ -654,7 +679,12 @@ impl<'a, 'b, 'tcx> FulfillProcessor<'a, 'b, 'tcx> { if obligation.predicate.is_known_global() { // no type variables present, can use evaluation for better caching. // FIXME: consider caching errors too. - if infcx.predicate_must_hold_considering_regions(obligation) { + // + // If the predicate is considered const, then we cannot use this because + // it will cause false negatives in the ui tests. + if !self.selcx.is_predicate_const(obligation.predicate) + && infcx.predicate_must_hold_considering_regions(obligation) + { debug!( "selecting trait at depth {} evaluated to holds", obligation.recursion_depth @@ -708,7 +738,12 @@ impl<'a, 'b, 'tcx> FulfillProcessor<'a, 'b, 'tcx> { if obligation.predicate.is_global(tcx) { // no type variables present, can use evaluation for better caching. // FIXME: consider caching errors too. - if self.selcx.infcx().predicate_must_hold_considering_regions(obligation) { + // + // If the predicate is considered const, then we cannot use this because + // it will cause false negatives in the ui tests. + if !self.selcx.is_predicate_const(obligation.predicate) + && self.selcx.infcx().predicate_must_hold_considering_regions(obligation) + { return ProcessResult::Changed(vec![]); } else { tracing::debug!("Does NOT hold: {:?}", obligation); diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs index d81b6949cae62..4bc22d5d73543 100644 --- a/compiler/rustc_trait_selection/src/traits/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/mod.rs @@ -33,7 +33,8 @@ use rustc_hir::lang_items::LangItem; use rustc_middle::ty::fold::TypeFoldable; use rustc_middle::ty::subst::{InternalSubsts, SubstsRef}; use rustc_middle::ty::{ - self, GenericParamDefKind, ToPredicate, Ty, TyCtxt, VtblEntry, COMMON_VTABLE_ENTRIES, + self, GenericParamDefKind, ToPredicate, Ty, TyCtxt, VtblEntry, WithConstness, + COMMON_VTABLE_ENTRIES, }; use rustc_span::{sym, Span}; use smallvec::SmallVec; @@ -306,11 +307,8 @@ pub fn normalize_param_env_or_error<'tcx>( debug!("normalize_param_env_or_error: elaborated-predicates={:?}", predicates); - let elaborated_env = ty::ParamEnv::new( - tcx.intern_predicates(&predicates), - unnormalized_env.reveal(), - unnormalized_env.constness(), - ); + let elaborated_env = + ty::ParamEnv::new(tcx.intern_predicates(&predicates), unnormalized_env.reveal()); // HACK: we are trying to normalize the param-env inside *itself*. The problem is that // normalization expects its param-env to be already normalized, which means we have @@ -362,11 +360,8 @@ pub fn normalize_param_env_or_error<'tcx>( // predicates here anyway. Keeping them here anyway because it seems safer. let outlives_env: Vec<_> = non_outlives_predicates.iter().chain(&outlives_predicates).cloned().collect(); - let outlives_env = ty::ParamEnv::new( - tcx.intern_predicates(&outlives_env), - unnormalized_env.reveal(), - unnormalized_env.constness(), - ); + let outlives_env = + ty::ParamEnv::new(tcx.intern_predicates(&outlives_env), unnormalized_env.reveal()); let outlives_predicates = match do_normalize_predicates( tcx, region_context, @@ -386,11 +381,7 @@ pub fn normalize_param_env_or_error<'tcx>( let mut predicates = non_outlives_predicates; predicates.extend(outlives_predicates); debug!("normalize_param_env_or_error: final predicates={:?}", predicates); - ty::ParamEnv::new( - tcx.intern_predicates(&predicates), - unnormalized_env.reveal(), - unnormalized_env.constness(), - ) + ty::ParamEnv::new(tcx.intern_predicates(&predicates), unnormalized_env.reveal()) } pub fn fully_normalize<'a, 'tcx, T>( @@ -573,17 +564,14 @@ fn prepare_vtable_segments<'tcx, T>( .predicates .into_iter() .filter_map(move |(pred, _)| { - pred.subst_supertrait(tcx, &inner_most_trait_ref).to_opt_poly_trait_pred() + pred.subst_supertrait(tcx, &inner_most_trait_ref).to_opt_poly_trait_ref() }); 'diving_in_skip_visited_traits: loop { if let Some(next_super_trait) = direct_super_traits_iter.next() { if visited.insert(next_super_trait.to_predicate(tcx)) { - // We're throwing away potential constness of super traits here. - // FIXME: handle ~const super traits - let next_super_trait = next_super_trait.map_bound(|t| t.trait_ref); stack.push(( - next_super_trait, + next_super_trait.value, emit_vptr_on_new_entry, Some(direct_super_traits_iter), )); @@ -615,11 +603,7 @@ fn prepare_vtable_segments<'tcx, T>( if let Some(siblings) = siblings_opt { if let Some(next_inner_most_trait_ref) = siblings.next() { if visited.insert(next_inner_most_trait_ref.to_predicate(tcx)) { - // We're throwing away potential constness of super traits here. - // FIXME: handle ~const super traits - let next_inner_most_trait_ref = - next_inner_most_trait_ref.map_bound(|t| t.trait_ref); - *inner_most_trait_ref = next_inner_most_trait_ref; + *inner_most_trait_ref = next_inner_most_trait_ref.value; *emit_vptr = emit_vptr_on_new_entry; break 'exiting_out; } else { diff --git a/compiler/rustc_trait_selection/src/traits/object_safety.rs b/compiler/rustc_trait_selection/src/traits/object_safety.rs index 412f7923fb586..afc546540d2e2 100644 --- a/compiler/rustc_trait_selection/src/traits/object_safety.rs +++ b/compiler/rustc_trait_selection/src/traits/object_safety.rs @@ -18,7 +18,7 @@ use rustc_errors::FatalError; use rustc_hir as hir; use rustc_hir::def_id::DefId; use rustc_middle::ty::subst::{GenericArg, InternalSubsts, Subst}; -use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable, TypeVisitor}; +use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable, TypeVisitor, WithConstness}; use rustc_middle::ty::{Predicate, ToPredicate}; use rustc_session::lint::builtin::WHERE_CLAUSES_OBJECT_SAFETY; use rustc_span::symbol::Symbol; @@ -698,11 +698,7 @@ fn receiver_is_dispatchable<'tcx>( .chain(array::IntoIter::new([unsize_predicate, trait_predicate])) .collect(); - ty::ParamEnv::new( - tcx.intern_predicates(&caller_bounds), - param_env.reveal(), - param_env.constness(), - ) + ty::ParamEnv::new(tcx.intern_predicates(&caller_bounds), param_env.reveal()) }; // Receiver: DispatchFromDyn U]> diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs index 79ed665681951..b8c66931cbe52 100644 --- a/compiler/rustc_trait_selection/src/traits/project.rs +++ b/compiler/rustc_trait_selection/src/traits/project.rs @@ -27,7 +27,7 @@ use rustc_hir::lang_items::LangItem; use rustc_infer::infer::resolve::OpportunisticRegionResolver; use rustc_middle::ty::fold::{TypeFoldable, TypeFolder}; use rustc_middle::ty::subst::Subst; -use rustc_middle::ty::{self, ToPredicate, Ty, TyCtxt}; +use rustc_middle::ty::{self, ToPredicate, Ty, TyCtxt, WithConstness}; use rustc_span::symbol::sym; use std::collections::BTreeMap; diff --git a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs index 89c01fe34400d..6e3e3b9b14480 100644 --- a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs +++ b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs @@ -11,7 +11,7 @@ use rustc_infer::traits::TraitEngine; use rustc_infer::traits::{Obligation, SelectionError, TraitObligation}; use rustc_lint_defs::builtin::DEREF_INTO_DYN_SUPERTRAIT; use rustc_middle::ty::print::with_no_trimmed_paths; -use rustc_middle::ty::{self, ToPredicate, Ty, TypeFoldable}; +use rustc_middle::ty::{self, ToPredicate, Ty, TypeFoldable, WithConstness}; use rustc_target::spec::abi::Abi; use crate::traits; @@ -303,7 +303,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { } else if lang_items.drop_trait() == Some(def_id) && obligation.predicate.skip_binder().constness == ty::BoundConstness::ConstIfConst { - if obligation.param_env.constness() == hir::Constness::Const { + if self.is_in_const_context { self.assemble_const_drop_candidates(obligation, stack, &mut candidates)?; } else { debug!("passing ~const Drop bound; in non-const context"); @@ -383,19 +383,17 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { .param_env .caller_bounds() .iter() - .filter_map(|o| o.to_opt_poly_trait_pred()); + .filter_map(|o| o.to_opt_poly_trait_ref()); // Micro-optimization: filter out predicates relating to different traits. let matching_bounds = - all_bounds.filter(|p| p.def_id() == stack.obligation.predicate.def_id()); + all_bounds.filter(|p| p.value.def_id() == stack.obligation.predicate.def_id()); // Keep only those bounds which may apply, and propagate overflow if it occurs. for bound in matching_bounds { - // FIXME(oli-obk): it is suspicious that we are dropping the constness and - // polarity here. - let wc = self.evaluate_where_clause(stack, bound.map_bound(|t| t.trait_ref))?; + let wc = self.evaluate_where_clause(stack, bound.value)?; if wc.may_apply() { - candidates.vec.push(ParamCandidate(bound)); + candidates.vec.push(ParamCandidate((bound, stack.obligation.polarity()))); } } diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs index e9b368f683e5b..2f1f7971a7926 100644 --- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs +++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs @@ -13,7 +13,7 @@ use rustc_infer::infer::InferOk; use rustc_infer::infer::LateBoundRegionConversionTime::HigherRankedType; use rustc_middle::ty::subst::{GenericArg, GenericArgKind, Subst, SubstsRef}; use rustc_middle::ty::{self, Ty}; -use rustc_middle::ty::{ToPolyTraitRef, ToPredicate}; +use rustc_middle::ty::{ToPolyTraitRef, ToPredicate, WithConstness}; use rustc_span::def_id::DefId; use crate::traits::project::{normalize_with_depth, normalize_with_depth_to}; @@ -58,9 +58,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { } ParamCandidate(param) => { - let obligations = - self.confirm_param_candidate(obligation, param.map_bound(|t| t.trait_ref)); - Ok(ImplSource::Param(obligations, param.skip_binder().constness)) + let obligations = self.confirm_param_candidate(obligation, param.0.value); + Ok(ImplSource::Param(obligations, param.0.constness)) } ImplCandidate(impl_def_id) => { @@ -140,7 +139,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { let trait_predicate = self.infcx.shallow_resolve(obligation.predicate); let placeholder_trait_predicate = - self.infcx().replace_bound_vars_with_placeholders(trait_predicate).trait_ref; + self.infcx().replace_bound_vars_with_placeholders(trait_predicate); let placeholder_self_ty = placeholder_trait_predicate.self_ty(); let placeholder_trait_predicate = ty::Binder::dummy(placeholder_trait_predicate); let (def_id, substs) = match *placeholder_self_ty.kind() { @@ -151,9 +150,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { let candidate_predicate = tcx.item_bounds(def_id)[idx].subst(tcx, substs); let candidate = candidate_predicate - .to_opt_poly_trait_pred() - .expect("projection candidate is not a trait predicate") - .map_bound(|t| t.trait_ref); + .to_opt_poly_trait_ref() + .expect("projection candidate is not a trait predicate"); let mut obligations = Vec::new(); let candidate = normalize_with_depth_to( self, @@ -167,7 +165,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { obligations.extend(self.infcx.commit_if_ok(|_| { self.infcx .at(&obligation.cause, obligation.param_env) - .sup(placeholder_trait_predicate, candidate) + .sup(placeholder_trait_predicate.to_poly_trait_ref(), candidate.value) .map(|InferOk { obligations, .. }| obligations) .map_err(|_| Unimplemented) })?); diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs index 2b120e855eb5a..32d04b55754fc 100644 --- a/compiler/rustc_trait_selection/src/traits/select/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs @@ -39,6 +39,7 @@ use rustc_middle::ty::fast_reject; use rustc_middle::ty::print::with_no_trimmed_paths; use rustc_middle::ty::relate::TypeRelation; use rustc_middle::ty::subst::{GenericArgKind, Subst, SubstsRef}; +use rustc_middle::ty::WithConstness; use rustc_middle::ty::{self, PolyProjectionPredicate, ToPolyTraitRef, ToPredicate}; use rustc_middle::ty::{Ty, TyCtxt, TypeFoldable}; use rustc_span::symbol::sym; @@ -127,6 +128,9 @@ pub struct SelectionContext<'cx, 'tcx> { /// and a negative impl allow_negative_impls: bool, + /// Are we in a const context that needs `~const` bounds to be const? + is_in_const_context: bool, + /// The mode that trait queries run in, which informs our error handling /// policy. In essence, canonicalized queries need their errors propagated /// rather than immediately reported because we do not have accurate spans. @@ -137,9 +141,9 @@ pub struct SelectionContext<'cx, 'tcx> { struct TraitObligationStack<'prev, 'tcx> { obligation: &'prev TraitObligation<'tcx>, - /// The trait predicate from `obligation` but "freshened" with the + /// The trait ref from `obligation` but "freshened" with the /// selection-context's freshener. Used to check for recursion. - fresh_trait_pred: ty::PolyTraitPredicate<'tcx>, + fresh_trait_ref: ty::ConstnessAnd>, /// Starts out equal to `depth` -- if, during evaluation, we /// encounter a cycle, then we will set this flag to the minimum @@ -218,6 +222,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { intercrate: false, intercrate_ambiguity_causes: None, allow_negative_impls: false, + is_in_const_context: false, query_mode: TraitQueryMode::Standard, } } @@ -229,6 +234,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { intercrate: true, intercrate_ambiguity_causes: None, allow_negative_impls: false, + is_in_const_context: false, query_mode: TraitQueryMode::Standard, } } @@ -244,6 +250,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { intercrate: false, intercrate_ambiguity_causes: None, allow_negative_impls, + is_in_const_context: false, query_mode: TraitQueryMode::Standard, } } @@ -259,10 +266,26 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { intercrate: false, intercrate_ambiguity_causes: None, allow_negative_impls: false, + is_in_const_context: false, query_mode, } } + pub fn with_constness( + infcx: &'cx InferCtxt<'cx, 'tcx>, + constness: hir::Constness, + ) -> SelectionContext<'cx, 'tcx> { + SelectionContext { + infcx, + freshener: infcx.freshener_keep_static(), + intercrate: false, + intercrate_ambiguity_causes: None, + allow_negative_impls: false, + is_in_const_context: matches!(constness, hir::Constness::Const), + query_mode: TraitQueryMode::Standard, + } + } + /// Enables tracking of intercrate ambiguity causes. These are /// used in coherence to give improved diagnostics. We don't do /// this until we detect a coherence error because it can lead to @@ -295,6 +318,20 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { self.intercrate } + /// Returns `true` if the trait predicate is considerd `const` to this selection context. + pub fn is_trait_predicate_const(&self, pred: ty::TraitPredicate<'_>) -> bool { + matches!(pred.constness, ty::BoundConstness::ConstIfConst) && self.is_in_const_context + } + + /// Returns `true` if the predicate is considered `const` to + /// this selection context. + pub fn is_predicate_const(&self, pred: ty::Predicate<'_>) -> bool { + match pred.kind().skip_binder() { + ty::PredicateKind::Trait(pred) => self.is_trait_predicate_const(pred), + _ => false, + } + } + /////////////////////////////////////////////////////////////////////////// // Selection // @@ -679,22 +716,20 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { } let stack = self.push_stack(previous_stack, &obligation); - let mut fresh_trait_pred = stack.fresh_trait_pred; - let mut param_env = obligation.param_env; - - fresh_trait_pred = fresh_trait_pred.map_bound(|mut pred| { - param_env = param_env.with_constness(pred.constness.and(param_env.constness())); - pred - }); + let fresh_trait_ref = stack.fresh_trait_ref; - debug!(?fresh_trait_pred); + debug!(?fresh_trait_ref); - if let Some(result) = self.check_evaluation_cache(param_env, fresh_trait_pred) { + if let Some(result) = self.check_evaluation_cache( + obligation.param_env, + fresh_trait_ref, + obligation.polarity(), + ) { debug!(?result, "CACHE HIT"); return Ok(result); } - if let Some(result) = stack.cache().get_provisional(fresh_trait_pred) { + if let Some(result) = stack.cache().get_provisional(fresh_trait_ref) { debug!(?result, "PROVISIONAL CACHE HIT"); stack.update_reached_depth(result.reached_depth); return Ok(result.result); @@ -719,12 +754,19 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { let reached_depth = stack.reached_depth.get(); if reached_depth >= stack.depth { debug!(?result, "CACHE MISS"); - self.insert_evaluation_cache(param_env, fresh_trait_pred, dep_node, result); + self.insert_evaluation_cache( + obligation.param_env, + fresh_trait_ref, + obligation.polarity(), + dep_node, + result, + ); - stack.cache().on_completion(stack.dfn, |fresh_trait_pred, provisional_result| { + stack.cache().on_completion(stack.dfn, |fresh_trait_ref, provisional_result| { self.insert_evaluation_cache( - param_env, - fresh_trait_pred, + obligation.param_env, + fresh_trait_ref, + obligation.polarity(), dep_node, provisional_result.max(result), ); @@ -734,10 +776,10 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { debug!( "caching provisionally because {:?} \ is a cycle participant (at depth {}, reached depth {})", - fresh_trait_pred, stack.depth, reached_depth, + fresh_trait_ref, stack.depth, reached_depth, ); - stack.cache().insert_provisional(stack.dfn, reached_depth, fresh_trait_pred, result); + stack.cache().insert_provisional(stack.dfn, reached_depth, fresh_trait_ref, result); } Ok(result) @@ -771,7 +813,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { .skip(1) // Skip top-most frame. .find(|prev| { stack.obligation.param_env == prev.obligation.param_env - && stack.fresh_trait_pred == prev.fresh_trait_pred + && stack.fresh_trait_ref == prev.fresh_trait_ref }) .map(|stack| stack.depth) { @@ -834,7 +876,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { // terms of `Fn` etc, but we could probably make this more // precise still. let unbound_input_types = - stack.fresh_trait_pred.skip_binder().trait_ref.substs.types().any(|ty| ty.is_fresh()); + stack.fresh_trait_ref.value.skip_binder().substs.types().any(|ty| ty.is_fresh()); if stack.obligation.polarity() != ty::ImplPolarity::Negative { // This check was an imperfect workaround for a bug in the old @@ -872,8 +914,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { && stack.iter().skip(1).any(|prev| { stack.obligation.param_env == prev.obligation.param_env && self.match_fresh_trait_refs( - stack.fresh_trait_pred, - prev.fresh_trait_pred, + stack.fresh_trait_ref, + prev.fresh_trait_ref, prev.obligation.param_env, ) }) @@ -951,7 +993,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { // not just the lifetime choice for this particular (non-erased) // predicate. // See issue #80691 - if stack.fresh_trait_pred.has_erased_regions() { + if stack.fresh_trait_ref.has_erased_regions() { result = result.max(EvaluatedToOkModuloRegions); } @@ -962,7 +1004,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { fn check_evaluation_cache( &self, param_env: ty::ParamEnv<'tcx>, - trait_pred: ty::PolyTraitPredicate<'tcx>, + trait_ref: ty::ConstnessAnd>, + polarity: ty::ImplPolarity, ) -> Option { // Neither the global nor local cache is aware of intercrate // mode, so don't do any caching. In particular, we might @@ -974,17 +1017,19 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { let tcx = self.tcx(); if self.can_use_global_caches(param_env) { - if let Some(res) = tcx.evaluation_cache.get(¶m_env.and(trait_pred), tcx) { + if let Some(res) = tcx.evaluation_cache.get(&(param_env.and(trait_ref), polarity), tcx) + { return Some(res); } } - self.infcx.evaluation_cache.get(¶m_env.and(trait_pred), tcx) + self.infcx.evaluation_cache.get(&(param_env.and(trait_ref), polarity), tcx) } fn insert_evaluation_cache( &mut self, param_env: ty::ParamEnv<'tcx>, - trait_pred: ty::PolyTraitPredicate<'tcx>, + trait_ref: ty::ConstnessAnd>, + polarity: ty::ImplPolarity, dep_node: DepNodeIndex, result: EvaluationResult, ) { @@ -1003,19 +1048,23 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { } if self.can_use_global_caches(param_env) { - if !trait_pred.needs_infer() { - debug!(?trait_pred, ?result, "insert_evaluation_cache global"); + if !trait_ref.needs_infer() { + debug!(?trait_ref, ?result, "insert_evaluation_cache global"); // This may overwrite the cache with the same value // FIXME: Due to #50507 this overwrites the different values // This should be changed to use HashMapExt::insert_same // when that is fixed - self.tcx().evaluation_cache.insert(param_env.and(trait_pred), dep_node, result); + self.tcx().evaluation_cache.insert( + (param_env.and(trait_ref), polarity), + dep_node, + result, + ); return; } } - debug!(?trait_pred, ?result, "insert_evaluation_cache"); - self.infcx.evaluation_cache.insert(param_env.and(trait_pred), dep_node, result); + debug!(?trait_ref, ?result, "insert_evaluation_cache"); + self.infcx.evaluation_cache.insert((param_env.and(trait_ref), polarity), dep_node, result); } /// For various reasons, it's possible for a subobligation @@ -1093,15 +1142,16 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { for candidate in candidates { // Respect const trait obligations - if obligation.is_const() { + if self.is_trait_predicate_const(obligation.predicate.skip_binder()) { match candidate { // const impl ImplCandidate(def_id) if tcx.impl_constness(def_id) == hir::Constness::Const => {} // const param - ParamCandidate(trait_pred) - if trait_pred.skip_binder().constness - == ty::BoundConstness::ConstIfConst => {} + ParamCandidate(( + ty::ConstnessAnd { constness: ty::BoundConstness::ConstIfConst, .. }, + _, + )) => {} // auto trait impl AutoImplCandidate(..) => {} // generator, this will raise error in other places @@ -1210,7 +1260,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { fn check_candidate_cache( &mut self, - mut param_env: ty::ParamEnv<'tcx>, + param_env: ty::ParamEnv<'tcx>, cache_fresh_trait_pred: ty::PolyTraitPredicate<'tcx>, ) -> Option>> { // Neither the global nor local cache is aware of intercrate @@ -1221,15 +1271,19 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { return None; } let tcx = self.tcx(); - let mut pred = cache_fresh_trait_pred.skip_binder(); - param_env = param_env.with_constness(pred.constness.and(param_env.constness())); - + let pred = &cache_fresh_trait_pred.skip_binder(); + let trait_ref = pred.trait_ref; if self.can_use_global_caches(param_env) { - if let Some(res) = tcx.selection_cache.get(¶m_env.and(pred), tcx) { + if let Some(res) = tcx + .selection_cache + .get(&(param_env.and(trait_ref).with_constness(pred.constness), pred.polarity), tcx) + { return Some(res); } } - self.infcx.selection_cache.get(¶m_env.and(pred), tcx) + self.infcx + .selection_cache + .get(&(param_env.and(trait_ref).with_constness(pred.constness), pred.polarity), tcx) } /// Determines whether can we safely cache the result @@ -1267,36 +1321,43 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { fn insert_candidate_cache( &mut self, - mut param_env: ty::ParamEnv<'tcx>, + param_env: ty::ParamEnv<'tcx>, cache_fresh_trait_pred: ty::PolyTraitPredicate<'tcx>, dep_node: DepNodeIndex, candidate: SelectionResult<'tcx, SelectionCandidate<'tcx>>, ) { let tcx = self.tcx(); - let mut pred = cache_fresh_trait_pred.skip_binder(); - - param_env = param_env.with_constness(pred.constness.and(param_env.constness())); + let pred = cache_fresh_trait_pred.skip_binder(); + let trait_ref = pred.trait_ref; if !self.can_cache_candidate(&candidate) { - debug!(?pred, ?candidate, "insert_candidate_cache - candidate is not cacheable"); + debug!(?trait_ref, ?candidate, "insert_candidate_cache - candidate is not cacheable"); return; } if self.can_use_global_caches(param_env) { if let Err(Overflow) = candidate { // Don't cache overflow globally; we only produce this in certain modes. - } else if !pred.needs_infer() { + } else if !trait_ref.needs_infer() { if !candidate.needs_infer() { - debug!(?pred, ?candidate, "insert_candidate_cache global"); + debug!(?trait_ref, ?candidate, "insert_candidate_cache global"); // This may overwrite the cache with the same value. - tcx.selection_cache.insert(param_env.and(pred), dep_node, candidate); + tcx.selection_cache.insert( + (param_env.and(trait_ref).with_constness(pred.constness), pred.polarity), + dep_node, + candidate, + ); return; } } } - debug!(?pred, ?candidate, "insert_candidate_cache local"); - self.infcx.selection_cache.insert(param_env.and(pred), dep_node, candidate); + debug!(?trait_ref, ?candidate, "insert_candidate_cache local"); + self.infcx.selection_cache.insert( + (param_env.and(trait_ref).with_constness(pred.constness), pred.polarity), + dep_node, + candidate, + ); } /// Matches a predicate against the bounds of its self type. @@ -1487,7 +1548,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { // Check if a bound would previously have been removed when normalizing // the param_env so that it can be given the lowest priority. See // #50825 for the motivation for this. - let is_global = |cand: &ty::PolyTraitPredicate<'tcx>| { + let is_global = |cand: &ty::PolyTraitRef<'tcx>| { cand.is_global(self.infcx.tcx) && !cand.has_late_bound_regions() }; @@ -1520,22 +1581,25 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { | ConstDropCandidate, ) => false, - (ParamCandidate(other), ParamCandidate(victim)) => { - let same_except_bound_vars = other.skip_binder().trait_ref - == victim.skip_binder().trait_ref - && other.skip_binder().constness == victim.skip_binder().constness - && other.skip_binder().polarity == victim.skip_binder().polarity - && !other.skip_binder().trait_ref.has_escaping_bound_vars(); + ( + ParamCandidate((other, other_polarity)), + ParamCandidate((victim, victim_polarity)), + ) => { + let same_except_bound_vars = other.value.skip_binder() + == victim.value.skip_binder() + && other.constness == victim.constness + && other_polarity == victim_polarity + && !other.value.skip_binder().has_escaping_bound_vars(); if same_except_bound_vars { // See issue #84398. In short, we can generate multiple ParamCandidates which are // the same except for unused bound vars. Just pick the one with the fewest bound vars // or the current one if tied (they should both evaluate to the same answer). This is // probably best characterized as a "hack", since we might prefer to just do our // best to *not* create essentially duplicate candidates in the first place. - other.bound_vars().len() <= victim.bound_vars().len() - } else if other.skip_binder().trait_ref == victim.skip_binder().trait_ref - && victim.skip_binder().constness == ty::BoundConstness::NotConst - && other.skip_binder().polarity == victim.skip_binder().polarity + other.value.bound_vars().len() <= victim.value.bound_vars().len() + } else if other.value == victim.value + && victim.constness == ty::BoundConstness::NotConst + && other_polarity == victim_polarity { // Drop otherwise equivalent non-const candidates in favor of const candidates. true @@ -1565,11 +1629,11 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { | TraitAliasCandidate(..) | ObjectCandidate(_) | ProjectionCandidate(_), - ) => !is_global(cand), + ) => !is_global(&cand.0.value), (ObjectCandidate(_) | ProjectionCandidate(_), ParamCandidate(ref cand)) => { // Prefer these to a global where-clause bound // (see issue #50825). - is_global(cand) + is_global(&cand.0.value) } ( ImplCandidate(_) @@ -1585,7 +1649,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { ) => { // Prefer these to a global where-clause bound // (see issue #50825). - is_global(cand) && other.evaluation.must_apply_modulo_regions() + is_global(&cand.0.value) && other.evaluation.must_apply_modulo_regions() } (ProjectionCandidate(i), ProjectionCandidate(j)) @@ -2145,8 +2209,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { fn match_fresh_trait_refs( &self, - previous: ty::PolyTraitPredicate<'tcx>, - current: ty::PolyTraitPredicate<'tcx>, + previous: ty::ConstnessAnd>, + current: ty::ConstnessAnd>, param_env: ty::ParamEnv<'tcx>, ) -> bool { let mut matcher = ty::_match::Match::new(self.tcx(), param_env); @@ -2158,13 +2222,17 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { previous_stack: TraitObligationStackList<'o, 'tcx>, obligation: &'o TraitObligation<'tcx>, ) -> TraitObligationStack<'o, 'tcx> { - let fresh_trait_pred = obligation.predicate.fold_with(&mut self.freshener); + let fresh_trait_ref = obligation + .predicate + .to_poly_trait_ref() + .fold_with(&mut self.freshener) + .with_constness(obligation.predicate.skip_binder().constness); let dfn = previous_stack.cache.next_dfn(); let depth = previous_stack.depth() + 1; TraitObligationStack { obligation, - fresh_trait_pred, + fresh_trait_ref, reached_depth: Cell::new(depth), previous: previous_stack, dfn, @@ -2358,7 +2426,7 @@ impl<'o, 'tcx> TraitObligationStack<'o, 'tcx> { debug!(reached_depth, "update_reached_depth"); let mut p = self; while reached_depth < p.depth { - debug!(?p.fresh_trait_pred, "update_reached_depth: marking as cycle participant"); + debug!(?p.fresh_trait_ref, "update_reached_depth: marking as cycle participant"); p.reached_depth.set(p.reached_depth.get().min(reached_depth)); p = p.previous.head.unwrap(); } @@ -2437,7 +2505,7 @@ struct ProvisionalEvaluationCache<'tcx> { /// - then we determine that `E` is in error -- we will then clear /// all cache values whose DFN is >= 4 -- in this case, that /// means the cached value for `F`. - map: RefCell, ProvisionalEvaluation>>, + map: RefCell>, ProvisionalEvaluation>>, } /// A cache value for the provisional cache: contains the depth-first @@ -2469,28 +2537,28 @@ impl<'tcx> ProvisionalEvaluationCache<'tcx> { /// `reached_depth` (from the returned value). fn get_provisional( &self, - fresh_trait_pred: ty::PolyTraitPredicate<'tcx>, + fresh_trait_ref: ty::ConstnessAnd>, ) -> Option { debug!( - ?fresh_trait_pred, + ?fresh_trait_ref, "get_provisional = {:#?}", - self.map.borrow().get(&fresh_trait_pred), + self.map.borrow().get(&fresh_trait_ref), ); - Some(*self.map.borrow().get(&fresh_trait_pred)?) + Some(*self.map.borrow().get(&fresh_trait_ref)?) } /// Insert a provisional result into the cache. The result came /// from the node with the given DFN. It accessed a minimum depth - /// of `reached_depth` to compute. It evaluated `fresh_trait_pred` + /// of `reached_depth` to compute. It evaluated `fresh_trait_ref` /// and resulted in `result`. fn insert_provisional( &self, from_dfn: usize, reached_depth: usize, - fresh_trait_pred: ty::PolyTraitPredicate<'tcx>, + fresh_trait_ref: ty::ConstnessAnd>, result: EvaluationResult, ) { - debug!(?from_dfn, ?fresh_trait_pred, ?result, "insert_provisional"); + debug!(?from_dfn, ?fresh_trait_ref, ?result, "insert_provisional"); let mut map = self.map.borrow_mut(); @@ -2514,7 +2582,7 @@ impl<'tcx> ProvisionalEvaluationCache<'tcx> { } } - map.insert(fresh_trait_pred, ProvisionalEvaluation { from_dfn, reached_depth, result }); + map.insert(fresh_trait_ref, ProvisionalEvaluation { from_dfn, reached_depth, result }); } /// Invoked when the node with dfn `dfn` does not get a successful @@ -2565,16 +2633,16 @@ impl<'tcx> ProvisionalEvaluationCache<'tcx> { fn on_completion( &self, dfn: usize, - mut op: impl FnMut(ty::PolyTraitPredicate<'tcx>, EvaluationResult), + mut op: impl FnMut(ty::ConstnessAnd>, EvaluationResult), ) { debug!(?dfn, "on_completion"); - for (fresh_trait_pred, eval) in + for (fresh_trait_ref, eval) in self.map.borrow_mut().drain_filter(|_k, eval| eval.from_dfn >= dfn) { - debug!(?fresh_trait_pred, ?eval, "on_completion"); + debug!(?fresh_trait_ref, ?eval, "on_completion"); - op(fresh_trait_pred, eval.result); + op(fresh_trait_ref, eval.result); } } } diff --git a/compiler/rustc_trait_selection/src/traits/specialize/mod.rs b/compiler/rustc_trait_selection/src/traits/specialize/mod.rs index ab732f510ff92..b64c55592272e 100644 --- a/compiler/rustc_trait_selection/src/traits/specialize/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/specialize/mod.rs @@ -508,9 +508,9 @@ crate fn to_pretty_impl_header(tcx: TyCtxt<'_>, impl_def_id: DefId) -> Option TraitAliasExpander<'tcx> { let items = predicates.predicates.iter().rev().filter_map(|(pred, span)| { pred.subst_supertrait(tcx, &trait_ref) - .to_opt_poly_trait_pred() - .map(|trait_ref| item.clone_and_push(trait_ref.map_bound(|t| t.trait_ref), *span)) + .to_opt_poly_trait_ref() + .map(|trait_ref| item.clone_and_push(trait_ref.value, *span)) }); debug!("expand_trait_aliases: items={:?}", items.clone()); @@ -183,8 +183,8 @@ impl Iterator for SupertraitDefIds<'tcx> { predicates .predicates .iter() - .filter_map(|(pred, _)| pred.to_opt_poly_trait_pred()) - .map(|trait_ref| trait_ref.def_id()) + .filter_map(|(pred, _)| pred.to_opt_poly_trait_ref()) + .map(|trait_ref| trait_ref.value.def_id()) .filter(|&super_def_id| visited.insert(super_def_id)), ); Some(def_id) diff --git a/compiler/rustc_trait_selection/src/traits/wf.rs b/compiler/rustc_trait_selection/src/traits/wf.rs index 5875b764e9f36..2a66684e2a2a0 100644 --- a/compiler/rustc_trait_selection/src/traits/wf.rs +++ b/compiler/rustc_trait_selection/src/traits/wf.rs @@ -6,7 +6,7 @@ use rustc_hir as hir; use rustc_hir::def_id::DefId; use rustc_hir::lang_items::LangItem; use rustc_middle::ty::subst::{GenericArg, GenericArgKind, SubstsRef}; -use rustc_middle::ty::{self, ToPredicate, Ty, TyCtxt, TypeFoldable}; +use rustc_middle::ty::{self, ToPredicate, Ty, TyCtxt, TypeFoldable, WithConstness}; use rustc_span::Span; use std::iter; @@ -298,10 +298,9 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> { let extend = |obligation: traits::PredicateObligation<'tcx>| { let mut cause = cause.clone(); - if let Some(parent_trait_ref) = obligation.predicate.to_opt_poly_trait_pred() { + if let Some(parent_trait_ref) = obligation.predicate.to_opt_poly_trait_ref() { let derived_cause = traits::DerivedObligationCause { - // FIXME(fee1-dead): when improving error messages, change this to PolyTraitPredicate - parent_trait_ref: parent_trait_ref.map_bound(|t| t.trait_ref), + parent_trait_ref: parent_trait_ref.value, parent_code: Lrc::new(obligation.cause.code.clone()), }; cause.make_mut().code = diff --git a/compiler/rustc_ty_utils/src/ty.rs b/compiler/rustc_ty_utils/src/ty.rs index f990709bd8d66..711a6f2fbebdd 100644 --- a/compiler/rustc_ty_utils/src/ty.rs +++ b/compiler/rustc_ty_utils/src/ty.rs @@ -2,7 +2,9 @@ use rustc_data_structures::fx::FxIndexSet; use rustc_hir as hir; use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_middle::ty::subst::Subst; -use rustc_middle::ty::{self, Binder, Predicate, PredicateKind, ToPredicate, Ty, TyCtxt}; +use rustc_middle::ty::{ + self, Binder, Predicate, PredicateKind, ToPredicate, Ty, TyCtxt, WithConstness, +}; use rustc_span::Span; use rustc_trait_selection::traits; @@ -280,79 +282,16 @@ fn param_env(tcx: TyCtxt<'_>, def_id: DefId) -> ty::ParamEnv<'_> { // issue #89334 predicates = tcx.expose_default_const_substs(predicates); - let local_did = def_id.as_local(); - let hir_id = local_did.map(|def_id| tcx.hir().local_def_id_to_hir_id(def_id)); + let unnormalized_env = + ty::ParamEnv::new(tcx.intern_predicates(&predicates), traits::Reveal::UserFacing); - let constness = match hir_id { - Some(hir_id) => match tcx.hir().get(hir_id) { - hir::Node::Item(hir::Item { kind: hir::ItemKind::Const(..), .. }) - | hir::Node::Item(hir::Item { kind: hir::ItemKind::Static(..), .. }) - | hir::Node::TraitItem(hir::TraitItem { - kind: hir::TraitItemKind::Const(..), .. - }) - | hir::Node::AnonConst(_) - | hir::Node::ImplItem(hir::ImplItem { kind: hir::ImplItemKind::Const(..), .. }) - | hir::Node::ImplItem(hir::ImplItem { - kind: - hir::ImplItemKind::Fn( - hir::FnSig { - header: hir::FnHeader { constness: hir::Constness::Const, .. }, - .. - }, - .., - ), - .. - }) => hir::Constness::Const, - - hir::Node::ImplItem(hir::ImplItem { - kind: hir::ImplItemKind::TyAlias(..) | hir::ImplItemKind::Fn(..), - .. - }) => { - let parent_hir_id = tcx.hir().get_parent_node(hir_id); - match tcx.hir().get(parent_hir_id) { - hir::Node::Item(hir::Item { - kind: hir::ItemKind::Impl(hir::Impl { constness, .. }), - .. - }) => *constness, - _ => span_bug!( - tcx.def_span(parent_hir_id.owner), - "impl item's parent node is not an impl", - ), - } - } - - hir::Node::Item(hir::Item { - kind: - hir::ItemKind::Fn(hir::FnSig { header: hir::FnHeader { constness, .. }, .. }, ..), - .. - }) - | hir::Node::TraitItem(hir::TraitItem { - kind: - hir::TraitItemKind::Fn( - hir::FnSig { header: hir::FnHeader { constness, .. }, .. }, - .., - ), - .. - }) - | hir::Node::Item(hir::Item { - kind: hir::ItemKind::Impl(hir::Impl { constness, .. }), - .. - }) => *constness, - - _ => hir::Constness::NotConst, - }, - None => hir::Constness::NotConst, - }; - - let unnormalized_env = ty::ParamEnv::new( - tcx.intern_predicates(&predicates), - traits::Reveal::UserFacing, - constness, - ); - - let body_id = hir_id.map_or(hir::CRATE_HIR_ID, |id| { - tcx.hir().maybe_body_owned_by(id).map_or(id, |body| body.hir_id) - }); + debug!("unnormalized_env caller bounds: {:?}", unnormalized_env.caller_bounds()); + let body_id = def_id + .as_local() + .map(|def_id| tcx.hir().local_def_id_to_hir_id(def_id)) + .map_or(hir::CRATE_HIR_ID, |id| { + tcx.hir().maybe_body_owned_by(id).map_or(id, |body| body.hir_id) + }); let cause = traits::ObligationCause::misc(tcx.def_span(def_id), body_id); traits::normalize_param_env_or_error(tcx, def_id, unnormalized_env, cause) } diff --git a/compiler/rustc_typeck/src/astconv/mod.rs b/compiler/rustc_typeck/src/astconv/mod.rs index b532a6b118f06..da751f2075399 100644 --- a/compiler/rustc_typeck/src/astconv/mod.rs +++ b/compiler/rustc_typeck/src/astconv/mod.rs @@ -1588,7 +1588,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { traits::transitive_bounds_that_define_assoc_type( tcx, predicates.iter().filter_map(|(p, _)| { - Some(p.to_opt_poly_trait_pred()?.map_bound(|t| t.trait_ref)) + p.to_opt_poly_trait_ref().map(|trait_ref| trait_ref.value) }), assoc_name, ) diff --git a/compiler/rustc_typeck/src/bounds.rs b/compiler/rustc_typeck/src/bounds.rs index 8bc3a48e5b506..24474e163b9da 100644 --- a/compiler/rustc_typeck/src/bounds.rs +++ b/compiler/rustc_typeck/src/bounds.rs @@ -1,7 +1,7 @@ //! Bounds are restrictions applied to some types after they've been converted into the //! `ty` form from the HIR. -use rustc_middle::ty::{self, ToPredicate, Ty, TyCtxt}; +use rustc_middle::ty::{self, ToPredicate, Ty, TyCtxt, WithConstness}; use rustc_span::Span; /// Collects together a list of type bounds. These lists of bounds occur in many places diff --git a/compiler/rustc_typeck/src/check/compare_method.rs b/compiler/rustc_typeck/src/check/compare_method.rs index 2001a4575d692..44fc81a889d17 100644 --- a/compiler/rustc_typeck/src/check/compare_method.rs +++ b/compiler/rustc_typeck/src/check/compare_method.rs @@ -208,11 +208,8 @@ fn compare_predicate_entailment<'tcx>( // The key step here is to update the caller_bounds's predicates to be // the new hybrid bounds we computed. let normalize_cause = traits::ObligationCause::misc(impl_m_span, impl_m_hir_id); - let param_env = ty::ParamEnv::new( - tcx.intern_predicates(&hybrid_preds.predicates), - Reveal::UserFacing, - hir::Constness::NotConst, - ); + let param_env = + ty::ParamEnv::new(tcx.intern_predicates(&hybrid_preds.predicates), Reveal::UserFacing); let param_env = traits::normalize_param_env_or_error(tcx, impl_m.def_id, param_env, normalize_cause); @@ -1168,11 +1165,8 @@ fn compare_type_predicate_entailment<'tcx>( debug!("compare_type_predicate_entailment: bounds={:?}", hybrid_preds); let normalize_cause = traits::ObligationCause::misc(impl_ty_span, impl_ty_hir_id); - let param_env = ty::ParamEnv::new( - tcx.intern_predicates(&hybrid_preds.predicates), - Reveal::UserFacing, - hir::Constness::NotConst, - ); + let param_env = + ty::ParamEnv::new(tcx.intern_predicates(&hybrid_preds.predicates), Reveal::UserFacing); let param_env = traits::normalize_param_env_or_error( tcx, impl_ty.def_id, @@ -1357,11 +1351,7 @@ pub fn check_type_bounds<'tcx>( .to_predicate(tcx), ), }; - ty::ParamEnv::new( - tcx.intern_predicates(&predicates), - Reveal::UserFacing, - param_env.constness(), - ) + ty::ParamEnv::new(tcx.intern_predicates(&predicates), Reveal::UserFacing) }; debug!(?normalize_param_env); @@ -1370,7 +1360,13 @@ pub fn check_type_bounds<'tcx>( impl_ty_substs.rebase_onto(tcx, impl_ty.container.id(), impl_trait_ref.substs); tcx.infer_ctxt().enter(move |infcx| { - let inh = Inherited::new(infcx, impl_ty.def_id.expect_local()); + let constness = impl_ty + .container + .impl_def_id() + .map(|did| tcx.impl_constness(did)) + .unwrap_or(hir::Constness::NotConst); + + let inh = Inherited::with_constness(infcx, impl_ty.def_id.expect_local(), constness); let infcx = &inh.infcx; let mut selcx = traits::SelectionContext::new(&infcx); @@ -1414,7 +1410,8 @@ pub fn check_type_bounds<'tcx>( // Check that all obligations are satisfied by the implementation's // version. - let errors = inh.fulfillment_cx.borrow_mut().select_all_or_error(&infcx); + let errors = + inh.fulfillment_cx.borrow_mut().select_all_with_constness_or_error(&infcx, constness); if !errors.is_empty() { infcx.report_fulfillment_errors(&errors, None, false); return Err(ErrorReported); diff --git a/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs b/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs index bc059df95249c..a02a7d7cbfeb2 100644 --- a/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs +++ b/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs @@ -616,7 +616,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { #[instrument(skip(self), level = "debug")] pub(in super::super) fn select_all_obligations_or_error(&self) { - let errors = self.fulfillment_cx.borrow_mut().select_all_or_error(&self); + let errors = self + .fulfillment_cx + .borrow_mut() + .select_all_with_constness_or_error(&self, self.inh.constness); if !errors.is_empty() { self.report_fulfillment_errors(&errors, self.inh.body_id, false); @@ -629,7 +632,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { fallback_has_occurred: bool, mutate_fulfillment_errors: impl Fn(&mut Vec>), ) { - let mut result = self.fulfillment_cx.borrow_mut().select_where_possible(self); + let mut result = self + .fulfillment_cx + .borrow_mut() + .select_with_constness_where_possible(self, self.inh.constness); if !result.is_empty() { mutate_fulfillment_errors(&mut result); self.report_fulfillment_errors(&result, self.inh.body_id, fallback_has_occurred); diff --git a/compiler/rustc_typeck/src/check/inherited.rs b/compiler/rustc_typeck/src/check/inherited.rs index bf52e77504331..f7552c1f4eb0c 100644 --- a/compiler/rustc_typeck/src/check/inherited.rs +++ b/compiler/rustc_typeck/src/check/inherited.rs @@ -53,6 +53,9 @@ pub struct Inherited<'a, 'tcx> { pub(super) deferred_generator_interiors: RefCell, hir::GeneratorKind)>>, + /// Reports whether this is in a const context. + pub(super) constness: hir::Constness, + pub(super) body_id: Option, /// Whenever we introduce an adjustment from `!` into a type variable, @@ -99,6 +102,16 @@ impl<'tcx> InheritedBuilder<'tcx> { impl Inherited<'a, 'tcx> { pub(super) fn new(infcx: InferCtxt<'a, 'tcx>, def_id: LocalDefId) -> Self { + let tcx = infcx.tcx; + let item_id = tcx.hir().local_def_id_to_hir_id(def_id); + Self::with_constness(infcx, def_id, tcx.hir().get(item_id).constness_for_typeck()) + } + + pub(super) fn with_constness( + infcx: InferCtxt<'a, 'tcx>, + def_id: LocalDefId, + constness: hir::Constness, + ) -> Self { let tcx = infcx.tcx; let item_id = tcx.hir().local_def_id_to_hir_id(def_id); let body_id = tcx.hir().maybe_body_owned_by(item_id); @@ -115,6 +128,7 @@ impl Inherited<'a, 'tcx> { deferred_cast_checks: RefCell::new(Vec::new()), deferred_generator_interiors: RefCell::new(Vec::new()), diverging_type_vars: RefCell::new(Default::default()), + constness, body_id, } } diff --git a/compiler/rustc_typeck/src/check/method/mod.rs b/compiler/rustc_typeck/src/check/method/mod.rs index 03518dc8d127e..dbc1d4ec19377 100644 --- a/compiler/rustc_typeck/src/check/method/mod.rs +++ b/compiler/rustc_typeck/src/check/method/mod.rs @@ -22,7 +22,7 @@ use rustc_infer::infer::{self, InferOk}; use rustc_middle::ty::subst::Subst; use rustc_middle::ty::subst::{InternalSubsts, SubstsRef}; use rustc_middle::ty::GenericParamDefKind; -use rustc_middle::ty::{self, ToPredicate, Ty, TypeFoldable}; +use rustc_middle::ty::{self, ToPredicate, Ty, TypeFoldable, WithConstness}; use rustc_span::symbol::Ident; use rustc_span::Span; use rustc_trait_selection::traits; diff --git a/compiler/rustc_typeck/src/check/method/probe.rs b/compiler/rustc_typeck/src/check/method/probe.rs index 9f9f0df97a894..9fd7e8c4daa20 100644 --- a/compiler/rustc_typeck/src/check/method/probe.rs +++ b/compiler/rustc_typeck/src/check/method/probe.rs @@ -21,7 +21,7 @@ use rustc_infer::infer::{self, InferOk, TyCtxtInferExt}; use rustc_middle::middle::stability; use rustc_middle::ty::subst::{InternalSubsts, Subst, SubstsRef}; use rustc_middle::ty::GenericParamDefKind; -use rustc_middle::ty::{self, ParamEnvAnd, ToPredicate, Ty, TyCtxt, TypeFoldable}; +use rustc_middle::ty::{self, ParamEnvAnd, ToPredicate, Ty, TyCtxt, TypeFoldable, WithConstness}; use rustc_session::lint; use rustc_span::def_id::LocalDefId; use rustc_span::lev_distance::{find_best_match_for_name, lev_distance}; diff --git a/compiler/rustc_typeck/src/check/method/suggest.rs b/compiler/rustc_typeck/src/check/method/suggest.rs index 6a3ce2132f815..ca174ed5e8497 100644 --- a/compiler/rustc_typeck/src/check/method/suggest.rs +++ b/compiler/rustc_typeck/src/check/method/suggest.rs @@ -12,7 +12,7 @@ use rustc_hir::{ExprKind, Node, QPath}; use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind}; use rustc_middle::ty::fast_reject::simplify_type; use rustc_middle::ty::print::with_crate_prefix; -use rustc_middle::ty::{self, ToPredicate, Ty, TyCtxt, TypeFoldable}; +use rustc_middle::ty::{self, ToPredicate, Ty, TyCtxt, TypeFoldable, WithConstness}; use rustc_span::lev_distance; use rustc_span::symbol::{kw, sym, Ident}; use rustc_span::{source_map, FileName, MultiSpan, Span, Symbol}; diff --git a/compiler/rustc_typeck/src/check/wfcheck.rs b/compiler/rustc_typeck/src/check/wfcheck.rs index a73dc339d7695..33a0c3275ca2a 100644 --- a/compiler/rustc_typeck/src/check/wfcheck.rs +++ b/compiler/rustc_typeck/src/check/wfcheck.rs @@ -21,6 +21,7 @@ use rustc_middle::ty::subst::{GenericArgKind, InternalSubsts, Subst}; use rustc_middle::ty::trait_def::TraitSpecializationKind; use rustc_middle::ty::{ self, AdtKind, GenericParamDefKind, ToPredicate, Ty, TyCtxt, TypeFoldable, TypeVisitor, + WithConstness, }; use rustc_session::parse::feature_err; use rustc_span::symbol::{sym, Ident, Symbol}; diff --git a/compiler/rustc_typeck/src/collect.rs b/compiler/rustc_typeck/src/collect.rs index bc41c230b115d..4b41730ffd50b 100644 --- a/compiler/rustc_typeck/src/collect.rs +++ b/compiler/rustc_typeck/src/collect.rs @@ -41,7 +41,7 @@ use rustc_middle::ty::subst::InternalSubsts; use rustc_middle::ty::util::Discr; use rustc_middle::ty::util::IntTypeExt; use rustc_middle::ty::{self, AdtKind, Const, DefIdTree, Ty, TyCtxt}; -use rustc_middle::ty::{ReprOptions, ToPredicate}; +use rustc_middle::ty::{ReprOptions, ToPredicate, WithConstness}; use rustc_session::lint; use rustc_session::parse::feature_err; use rustc_span::symbol::{kw, sym, Ident, Symbol}; diff --git a/src/librustdoc/clean/blanket_impl.rs b/src/librustdoc/clean/blanket_impl.rs index 7ca5cb4bd4279..f44589f60675f 100644 --- a/src/librustdoc/clean/blanket_impl.rs +++ b/src/librustdoc/clean/blanket_impl.rs @@ -3,7 +3,7 @@ use rustc_hir as hir; use rustc_infer::infer::{InferOk, TyCtxtInferExt}; use rustc_infer::traits; use rustc_middle::ty::subst::Subst; -use rustc_middle::ty::ToPredicate; +use rustc_middle::ty::{ToPredicate, WithConstness}; use rustc_span::DUMMY_SP; use super::*; @@ -66,8 +66,7 @@ impl<'a, 'tcx> BlanketImplFinder<'a, 'tcx> { .into_iter() .chain(Some( ty::Binder::dummy(trait_ref) - .to_poly_trait_predicate() - .map_bound(ty::PredicateKind::Trait) + .without_const() .to_predicate(infcx.tcx), )); for predicate in predicates { diff --git a/src/test/ui/infinite/infinite-struct.stderr b/src/test/ui/infinite/infinite-struct.stderr index 383e13fd4b09d..369645f9030fb 100644 --- a/src/test/ui/infinite/infinite-struct.stderr +++ b/src/test/ui/infinite/infinite-struct.stderr @@ -19,7 +19,7 @@ LL | struct Take(Take); | ^^^^^^^^^^^^^^^^^^ | = note: ...which immediately requires computing drop-check constraints for `Take` again - = note: cycle used when computing dropck types for `Canonical { max_universe: U0, variables: [], value: ParamEnvAnd { param_env: ParamEnv { caller_bounds: [], reveal: UserFacing, constness: NotConst }, value: Take } }` + = note: cycle used when computing dropck types for `Canonical { max_universe: U0, variables: [], value: ParamEnvAnd { param_env: ParamEnv { caller_bounds: [], reveal: UserFacing }, value: Take } }` error: aborting due to 2 previous errors diff --git a/src/test/ui/infinite/infinite-tag-type-recursion.stderr b/src/test/ui/infinite/infinite-tag-type-recursion.stderr index 1802c7599a3b5..61b5e94677526 100644 --- a/src/test/ui/infinite/infinite-tag-type-recursion.stderr +++ b/src/test/ui/infinite/infinite-tag-type-recursion.stderr @@ -18,7 +18,7 @@ LL | enum MList { Cons(isize, MList), Nil } | ^^^^^^^^^^ | = note: ...which immediately requires computing drop-check constraints for `MList` again - = note: cycle used when computing dropck types for `Canonical { max_universe: U0, variables: [], value: ParamEnvAnd { param_env: ParamEnv { caller_bounds: [], reveal: UserFacing, constness: NotConst }, value: MList } }` + = note: cycle used when computing dropck types for `Canonical { max_universe: U0, variables: [], value: ParamEnvAnd { param_env: ParamEnv { caller_bounds: [], reveal: UserFacing }, value: MList } }` error: aborting due to 2 previous errors diff --git a/src/test/ui/rfc-2632-const-trait-impl/assoc-type.rs b/src/test/ui/rfc-2632-const-trait-impl/assoc-type.rs index 7b012083c5a3d..228b5ed71e80a 100644 --- a/src/test/ui/rfc-2632-const-trait-impl/assoc-type.rs +++ b/src/test/ui/rfc-2632-const-trait-impl/assoc-type.rs @@ -1,5 +1,6 @@ // FIXME(fee1-dead): this should have a better error message #![feature(const_trait_impl)] + struct NonConstAdd(i32); impl std::ops::Add for NonConstAdd { diff --git a/src/test/ui/rfc-2632-const-trait-impl/assoc-type.stderr b/src/test/ui/rfc-2632-const-trait-impl/assoc-type.stderr index d1e55e12d6f50..b894092205e43 100644 --- a/src/test/ui/rfc-2632-const-trait-impl/assoc-type.stderr +++ b/src/test/ui/rfc-2632-const-trait-impl/assoc-type.stderr @@ -1,12 +1,12 @@ error[E0277]: cannot add `NonConstAdd` to `NonConstAdd` - --> $DIR/assoc-type.rs:18:5 + --> $DIR/assoc-type.rs:19:5 | LL | type Bar = NonConstAdd; | ^^^^^^^^^^^^^^^^^^^^^^^ no implementation for `NonConstAdd + NonConstAdd` | = help: the trait `Add` is not implemented for `NonConstAdd` note: required by a bound in `Foo::Bar` - --> $DIR/assoc-type.rs:14:15 + --> $DIR/assoc-type.rs:15:15 | LL | type Bar: ~const std::ops::Add; | ^^^^^^^^^^^^^^^^^^^^ required by this bound in `Foo::Bar` diff --git a/src/tools/clippy/clippy_lints/src/future_not_send.rs b/src/tools/clippy/clippy_lints/src/future_not_send.rs index a9297adb426a2..6b2ac985555dc 100644 --- a/src/tools/clippy/clippy_lints/src/future_not_send.rs +++ b/src/tools/clippy/clippy_lints/src/future_not_send.rs @@ -67,8 +67,8 @@ impl<'tcx> LateLintPass<'tcx> for FutureNotSend { let mut is_future = false; for &(p, _span) in preds { let p = p.subst(cx.tcx, subst); - if let Some(trait_pred) = p.to_opt_poly_trait_pred() { - if Some(trait_pred.skip_binder().trait_ref.def_id) == cx.tcx.lang_items().future_trait() { + if let Some(trait_ref) = p.to_opt_poly_trait_ref() { + if Some(trait_ref.value.def_id()) == cx.tcx.lang_items().future_trait() { is_future = true; break; }