diff options
| -rw-r--r-- | src/librustc/middle/traits/fulfill.rs | 80 | ||||
| -rw-r--r-- | src/librustc/middle/traits/mod.rs | 8 | ||||
| -rw-r--r-- | src/librustc/middle/traits/select.rs | 4 | ||||
| -rw-r--r-- | src/librustc/middle/ty/context.rs | 5 | ||||
| -rw-r--r-- | src/librustc/middle/ty/mod.rs | 11 | ||||
| -rw-r--r-- | src/test/compile-fail/dep-graph-trait-impl.rs | 4 |
6 files changed, 80 insertions, 32 deletions
diff --git a/src/librustc/middle/traits/fulfill.rs b/src/librustc/middle/traits/fulfill.rs index bdf1c4645c0..d28504db585 100644 --- a/src/librustc/middle/traits/fulfill.rs +++ b/src/librustc/middle/traits/fulfill.rs @@ -8,6 +8,7 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. +use dep_graph::DepGraph; use middle::infer::InferCtxt; use middle::ty::{self, Ty, TypeFoldable}; use rustc_data_structures::obligation_forest::{Backtrace, ObligationForest, Error}; @@ -30,7 +31,12 @@ use super::select::SelectionContext; use super::Unimplemented; use super::util::predicate_for_builtin_bound; -pub struct FulfilledPredicates<'tcx> { +pub struct GlobalFulfilledPredicates<'tcx> { + set: FnvHashSet<ty::PolyTraitPredicate<'tcx>>, + dep_graph: DepGraph, +} + +pub struct LocalFulfilledPredicates<'tcx> { set: FnvHashSet<ty::Predicate<'tcx>> } @@ -56,7 +62,7 @@ pub struct FulfillmentContext<'tcx> { // initially-distinct type variables are unified after being // inserted. Deduplicating the predicate set on selection had a // significant performance cost the last time I checked. - duplicate_set: FulfilledPredicates<'tcx>, + duplicate_set: LocalFulfilledPredicates<'tcx>, // A list of all obligations that have been registered with this // fulfillment context. @@ -106,7 +112,7 @@ impl<'tcx> FulfillmentContext<'tcx> { /// Creates a new fulfillment context. pub fn new() -> FulfillmentContext<'tcx> { FulfillmentContext { - duplicate_set: FulfilledPredicates::new(), + duplicate_set: LocalFulfilledPredicates::new(), predicates: ObligationForest::new(), region_obligations: NodeMap(), } @@ -240,7 +246,7 @@ impl<'tcx> FulfillmentContext<'tcx> { // local cache). This is because the tcx cache maintains the // invariant that it only contains things that have been // proven, and we have not yet proven that `predicate` holds. - if predicate.is_global() && tcx.fulfilled_predicates.borrow().is_duplicate(predicate) { + if tcx.fulfilled_predicates.borrow().check_duplicate(predicate) { return true; } @@ -283,10 +289,7 @@ impl<'tcx> FulfillmentContext<'tcx> { // these are obligations that were proven to be true. for pending_obligation in outcome.completed { let predicate = &pending_obligation.obligation.predicate; - if predicate.is_global() { - selcx.tcx().fulfilled_predicates.borrow_mut() - .is_duplicate_or_add(predicate); - } + selcx.tcx().fulfilled_predicates.borrow_mut().add_if_global(predicate); } errors.extend( @@ -329,6 +332,8 @@ fn process_predicate<'a,'tcx>(selcx: &mut SelectionContext<'a,'tcx>, // However, this is a touch tricky, so I'm doing something // a bit hackier for now so that the `huge-struct.rs` passes. + let tcx = selcx.tcx(); + let retain_vec: Vec<_> = { let mut dedup = FnvHashSet(); v.iter() @@ -336,10 +341,7 @@ fn process_predicate<'a,'tcx>(selcx: &mut SelectionContext<'a,'tcx>, // Screen out obligations that we know globally // are true. This should really be the DAG check // mentioned above. - if - o.predicate.is_global() && - selcx.tcx().fulfilled_predicates.borrow().is_duplicate(&o.predicate) - { + if tcx.fulfilled_predicates.borrow().check_duplicate(&o.predicate) { return false; } @@ -611,22 +613,62 @@ fn register_region_obligation<'tcx>(t_a: Ty<'tcx>, } -impl<'tcx> FulfilledPredicates<'tcx> { - pub fn new() -> FulfilledPredicates<'tcx> { - FulfilledPredicates { +impl<'tcx> LocalFulfilledPredicates<'tcx> { + pub fn new() -> LocalFulfilledPredicates<'tcx> { + LocalFulfilledPredicates { set: FnvHashSet() } } - pub fn is_duplicate(&self, key: &ty::Predicate<'tcx>) -> bool { - self.set.contains(key) - } - fn is_duplicate_or_add(&mut self, key: &ty::Predicate<'tcx>) -> bool { + // For a `LocalFulfilledPredicates`, if we find a match, we + // don't need to add a read edge to the dep-graph. This is + // because it means that the predicate has already been + // considered by this `FulfillmentContext`, and hence the + // containing task will already have an edge. (Here we are + // assuming each `FulfillmentContext` only gets used from one + // task; but to do otherwise makes no sense) !self.set.insert(key.clone()) } } +impl<'tcx> GlobalFulfilledPredicates<'tcx> { + pub fn new(dep_graph: DepGraph) -> GlobalFulfilledPredicates<'tcx> { + GlobalFulfilledPredicates { + set: FnvHashSet(), + dep_graph: dep_graph, + } + } + + pub fn check_duplicate(&self, key: &ty::Predicate<'tcx>) -> bool { + if let ty::Predicate::Trait(ref data) = *key { + // For the global predicate registry, when we find a match, it + // may have been computed by some other task, so we want to + // add a read from the node corresponding to the predicate + // processing to make sure we get the transitive dependencies. + if self.set.contains(data) { + debug_assert!(data.is_global()); + self.dep_graph.read(data.dep_node()); + return true; + } + } + + return false; + } + + fn add_if_global(&mut self, key: &ty::Predicate<'tcx>) { + if let ty::Predicate::Trait(ref data) = *key { + // We only add things to the global predicate registry + // after the current task has proved them, and hence + // already has the required read edges, so we don't need + // to add any more edges here. + if data.is_global() { + self.set.insert(data.clone()); + } + } + } +} + fn to_fulfillment_error<'tcx>( error: Error<PendingPredicateObligation<'tcx>, FulfillmentErrorCode<'tcx>>) -> FulfillmentError<'tcx> diff --git a/src/librustc/middle/traits/mod.rs b/src/librustc/middle/traits/mod.rs index f58cc919959..f0ff0380aaa 100644 --- a/src/librustc/middle/traits/mod.rs +++ b/src/librustc/middle/traits/mod.rs @@ -15,7 +15,6 @@ pub use self::FulfillmentErrorCode::*; pub use self::Vtable::*; pub use self::ObligationCauseCode::*; -use dep_graph::DepNode; use middle::def_id::DefId; use middle::free_region::FreeRegionMap; use middle::subst; @@ -36,7 +35,7 @@ pub use self::error_reporting::report_object_safety_error; pub use self::coherence::orphan_check; pub use self::coherence::overlapping_impls; pub use self::coherence::OrphanCheckErr; -pub use self::fulfill::{FulfillmentContext, FulfilledPredicates, RegionObligation}; +pub use self::fulfill::{FulfillmentContext, GlobalFulfilledPredicates, RegionObligation}; pub use self::project::MismatchedProjectionTypes; pub use self::project::normalize; pub use self::project::Normalized; @@ -616,11 +615,6 @@ impl<'tcx> FulfillmentError<'tcx> { } impl<'tcx> TraitObligation<'tcx> { - /// Creates the dep-node for selecting/evaluating this trait reference. - fn dep_node(&self) -> DepNode { - DepNode::TraitSelect(self.predicate.def_id()) - } - fn self_ty(&self) -> ty::Binder<Ty<'tcx>> { ty::Binder(self.predicate.skip_binder().self_ty()) } diff --git a/src/librustc/middle/traits/select.rs b/src/librustc/middle/traits/select.rs index 59a62d130b8..61418734b67 100644 --- a/src/librustc/middle/traits/select.rs +++ b/src/librustc/middle/traits/select.rs @@ -307,7 +307,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { debug!("select({:?})", obligation); assert!(!obligation.predicate.has_escaping_regions()); - let dep_node = obligation.dep_node(); + let dep_node = obligation.predicate.dep_node(); let _task = self.tcx().dep_graph.in_task(dep_node); let stack = self.push_stack(TraitObligationStackList::empty(), obligation); @@ -462,7 +462,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { // have been proven elsewhere. This cache only contains // predicates that are global in scope and hence unaffected by // the current environment. - if self.tcx().fulfilled_predicates.borrow().is_duplicate(&obligation.predicate) { + if self.tcx().fulfilled_predicates.borrow().check_duplicate(&obligation.predicate) { return EvaluatedToOk; } diff --git a/src/librustc/middle/ty/context.rs b/src/librustc/middle/ty/context.rs index d1504d25288..bf768a40999 100644 --- a/src/librustc/middle/ty/context.rs +++ b/src/librustc/middle/ty/context.rs @@ -367,7 +367,7 @@ pub struct ctxt<'tcx> { /// This is used to avoid duplicate work. Predicates are only /// added to this set when they mention only "global" names /// (i.e., no type or lifetime parameters). - pub fulfilled_predicates: RefCell<traits::FulfilledPredicates<'tcx>>, + pub fulfilled_predicates: RefCell<traits::GlobalFulfilledPredicates<'tcx>>, /// Caches the representation hints for struct definitions. repr_hint_cache: RefCell<DepTrackingMap<maps::ReprHints<'tcx>>>, @@ -510,6 +510,7 @@ impl<'tcx> ctxt<'tcx> { let interner = RefCell::new(FnvHashMap()); let common_types = CommonTypes::new(&arenas.type_, &interner); let dep_graph = DepGraph::new(s.opts.incremental_compilation); + let fulfilled_predicates = traits::GlobalFulfilledPredicates::new(dep_graph.clone()); tls::enter(ctxt { arenas: arenas, interner: interner, @@ -532,7 +533,7 @@ impl<'tcx> ctxt<'tcx> { adt_defs: RefCell::new(DepTrackingMap::new(dep_graph.clone())), predicates: RefCell::new(DepTrackingMap::new(dep_graph.clone())), super_predicates: RefCell::new(DepTrackingMap::new(dep_graph.clone())), - fulfilled_predicates: RefCell::new(traits::FulfilledPredicates::new()), + fulfilled_predicates: RefCell::new(fulfilled_predicates), map: map, freevars: RefCell::new(freevars), tcache: RefCell::new(DepTrackingMap::new(dep_graph.clone())), diff --git a/src/librustc/middle/ty/mod.rs b/src/librustc/middle/ty/mod.rs index b902a46fea3..e25c05f6272 100644 --- a/src/librustc/middle/ty/mod.rs +++ b/src/librustc/middle/ty/mod.rs @@ -838,6 +838,11 @@ impl<'tcx> TraitPredicate<'tcx> { self.trait_ref.def_id } + /// Creates the dep-node for selecting/evaluating this trait reference. + fn dep_node(&self) -> DepNode { + DepNode::TraitSelect(self.def_id()) + } + pub fn input_types(&self) -> &[Ty<'tcx>] { self.trait_ref.substs.types.as_slice() } @@ -849,8 +854,14 @@ impl<'tcx> TraitPredicate<'tcx> { impl<'tcx> PolyTraitPredicate<'tcx> { pub fn def_id(&self) -> DefId { + // ok to skip binder since trait def-id does not care about regions self.0.def_id() } + + pub fn dep_node(&self) -> DepNode { + // ok to skip binder since depnode does not care about regions + self.0.dep_node() + } } #[derive(Clone, PartialEq, Eq, Hash, Debug)] diff --git a/src/test/compile-fail/dep-graph-trait-impl.rs b/src/test/compile-fail/dep-graph-trait-impl.rs index 83e924fe06d..4a7becca15d 100644 --- a/src/test/compile-fail/dep-graph-trait-impl.rs +++ b/src/test/compile-fail/dep-graph-trait-impl.rs @@ -41,7 +41,7 @@ mod y { } // FIXME(#30741) tcx fulfillment cache not tracked - #[rustc_then_this_would_need(TypeckItemBody)] //~ ERROR no path + #[rustc_then_this_would_need(TypeckItemBody)] //~ ERROR OK #[rustc_then_this_would_need(TransCrateItem)] //~ ERROR no path pub fn take_foo_with_char() { take_foo::<char>('a'); @@ -54,7 +54,7 @@ mod y { } // FIXME(#30741) tcx fulfillment cache not tracked - #[rustc_then_this_would_need(TypeckItemBody)] //~ ERROR no path + #[rustc_then_this_would_need(TypeckItemBody)] //~ ERROR OK #[rustc_then_this_would_need(TransCrateItem)] //~ ERROR no path pub fn take_foo_with_u32() { take_foo::<u32>(22); |