diff options
| -rw-r--r-- | src/librustc_infer/traits/mod.rs | 2 | ||||
| -rw-r--r-- | src/librustc_infer/traits/util.rs | 10 | ||||
| -rw-r--r-- | src/librustc_middle/traits/mod.rs | 52 | ||||
| -rw-r--r-- | src/librustc_middle/traits/structural_impls.rs | 6 | ||||
| -rw-r--r-- | src/librustc_mir/borrow_check/type_check/mod.rs | 2 | ||||
| -rw-r--r-- | src/librustc_trait_selection/traits/fulfill.rs | 2 | ||||
| -rw-r--r-- | src/librustc_trait_selection/traits/misc.rs | 2 | ||||
| -rw-r--r-- | src/librustc_trait_selection/traits/wf.rs | 7 | ||||
| -rw-r--r-- | src/librustc_typeck/check/compare_method.rs | 32 | ||||
| -rw-r--r-- | src/librustc_typeck/check/mod.rs | 6 |
10 files changed, 83 insertions, 38 deletions
diff --git a/src/librustc_infer/traits/mod.rs b/src/librustc_infer/traits/mod.rs index 892a62855a0..7f644d42437 100644 --- a/src/librustc_infer/traits/mod.rs +++ b/src/librustc_infer/traits/mod.rs @@ -59,7 +59,7 @@ pub type TraitObligation<'tcx> = Obligation<'tcx, ty::PolyTraitPredicate<'tcx>>; // `PredicateObligation` is used a lot. Make sure it doesn't unintentionally get bigger. #[cfg(target_arch = "x86_64")] -static_assert_size!(PredicateObligation<'_>, 88); +static_assert_size!(PredicateObligation<'_>, 48); pub type Obligations<'tcx, O> = Vec<Obligation<'tcx, O>>; pub type PredicateObligations<'tcx> = Vec<PredicateObligation<'tcx>>; diff --git a/src/librustc_infer/traits/util.rs b/src/librustc_infer/traits/util.rs index 8081cac0067..ee9846c64b6 100644 --- a/src/librustc_infer/traits/util.rs +++ b/src/librustc_infer/traits/util.rs @@ -142,10 +142,12 @@ fn predicate_obligation<'tcx>( predicate: ty::Predicate<'tcx>, span: Option<Span>, ) -> PredicateObligation<'tcx> { - let mut cause = ObligationCause::dummy(); - if let Some(span) = span { - cause.span = span; - } + let cause = if let Some(span) = span { + ObligationCause::dummy_with_span(span) + } else { + ObligationCause::dummy() + }; + Obligation { cause, param_env: ty::ParamEnv::empty(), recursion_depth: 0, predicate } } diff --git a/src/librustc_middle/traits/mod.rs b/src/librustc_middle/traits/mod.rs index 9afab5a4d2f..113ddc42b41 100644 --- a/src/librustc_middle/traits/mod.rs +++ b/src/librustc_middle/traits/mod.rs @@ -20,7 +20,8 @@ use rustc_span::{Span, DUMMY_SP}; use smallvec::SmallVec; use std::borrow::Cow; -use std::fmt::Debug; +use std::fmt; +use std::ops::Deref; use std::rc::Rc; pub use self::select::{EvaluationCache, EvaluationResult, OverflowError, SelectionCache}; @@ -80,8 +81,40 @@ pub enum Reveal { } /// The reason why we incurred this obligation; used for error reporting. -#[derive(Clone, Debug, PartialEq, Eq, Hash)] +/// +/// As the happy path does not care about this struct, storing this on the heap +/// ends up increasing performance. +/// +/// We do not want to intern this as there are a lot of obligation causes which +/// only live for a short period of time. +#[derive(Clone, PartialEq, Eq, Hash)] pub struct ObligationCause<'tcx> { + data: Rc<ObligationCauseData<'tcx>>, +} + +// A dummy obligation. As the parralel compiler does not share `Obligation`s between +// threads, we use a `thread_local` here so we can keep using an `Rc` inside of `ObligationCause`. +thread_local! { + static DUMMY_OBLIGATION_CAUSE: ObligationCause<'static> = ObligationCause::new(DUMMY_SP, hir::CRATE_HIR_ID, MiscObligation); +} + +// Correctly format `ObligationCause::dummy`. +impl<'tcx> fmt::Debug for ObligationCause<'tcx> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + ObligationCauseData::fmt(self, f) + } +} + +impl Deref for ObligationCause<'tcx> { + type Target = ObligationCauseData<'tcx>; + + fn deref(&self) -> &Self::Target { + &self.data + } +} + +#[derive(Clone, Debug, PartialEq, Eq, Hash)] +pub struct ObligationCauseData<'tcx> { pub span: Span, /// The ID of the fn body that triggered this obligation. This is @@ -102,15 +135,24 @@ impl<'tcx> ObligationCause<'tcx> { body_id: hir::HirId, code: ObligationCauseCode<'tcx>, ) -> ObligationCause<'tcx> { - ObligationCause { span, body_id, code } + ObligationCause { data: Rc::new(ObligationCauseData { span, body_id, code }) } } pub fn misc(span: Span, body_id: hir::HirId) -> ObligationCause<'tcx> { - ObligationCause { span, body_id, code: MiscObligation } + ObligationCause::new(span, body_id, MiscObligation) } + pub fn dummy_with_span(span: Span) -> ObligationCause<'tcx> { + ObligationCause::new(span, hir::CRATE_HIR_ID, MiscObligation) + } + + #[inline(always)] pub fn dummy() -> ObligationCause<'tcx> { - ObligationCause { span: DUMMY_SP, body_id: hir::CRATE_HIR_ID, code: MiscObligation } + DUMMY_OBLIGATION_CAUSE.with(Clone::clone) + } + + pub fn make_mut(&mut self) -> &mut ObligationCauseData<'tcx> { + Rc::make_mut(&mut self.data) } pub fn span(&self, tcx: TyCtxt<'tcx>) -> Span { diff --git a/src/librustc_middle/traits/structural_impls.rs b/src/librustc_middle/traits/structural_impls.rs index 74f74415294..a9a370615ed 100644 --- a/src/librustc_middle/traits/structural_impls.rs +++ b/src/librustc_middle/traits/structural_impls.rs @@ -232,11 +232,7 @@ impl<'a, 'tcx> Lift<'tcx> for traits::DerivedObligationCause<'a> { impl<'a, 'tcx> Lift<'tcx> for traits::ObligationCause<'a> { type Lifted = traits::ObligationCause<'tcx>; fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> { - tcx.lift(&self.code).map(|code| traits::ObligationCause { - span: self.span, - body_id: self.body_id, - code, - }) + tcx.lift(&self.code).map(|code| traits::ObligationCause::new(self.span, self.body_id, code)) } } diff --git a/src/librustc_mir/borrow_check/type_check/mod.rs b/src/librustc_mir/borrow_check/type_check/mod.rs index 377a0b6f25c..da80e777f32 100644 --- a/src/librustc_mir/borrow_check/type_check/mod.rs +++ b/src/librustc_mir/borrow_check/type_check/mod.rs @@ -1245,7 +1245,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> { |infcx| { let mut obligations = ObligationAccumulator::default(); - let dummy_body_id = ObligationCause::dummy().body_id; + let dummy_body_id = hir::CRATE_HIR_ID; let (output_ty, opaque_type_map) = obligations.add(infcx.instantiate_opaque_types( anon_owner_def_id, diff --git a/src/librustc_trait_selection/traits/fulfill.rs b/src/librustc_trait_selection/traits/fulfill.rs index 51c62dbb88c..5c0c80b3a3f 100644 --- a/src/librustc_trait_selection/traits/fulfill.rs +++ b/src/librustc_trait_selection/traits/fulfill.rs @@ -84,7 +84,7 @@ pub struct PendingPredicateObligation<'tcx> { // `PendingPredicateObligation` is used a lot. Make sure it doesn't unintentionally get bigger. #[cfg(target_arch = "x86_64")] -static_assert_size!(PendingPredicateObligation<'_>, 112); +static_assert_size!(PendingPredicateObligation<'_>, 72); impl<'a, 'tcx> FulfillmentContext<'tcx> { /// Creates a new fulfillment context. diff --git a/src/librustc_trait_selection/traits/misc.rs b/src/librustc_trait_selection/traits/misc.rs index 7403b936391..61567aeb57c 100644 --- a/src/librustc_trait_selection/traits/misc.rs +++ b/src/librustc_trait_selection/traits/misc.rs @@ -48,7 +48,7 @@ pub fn can_type_implement_copy( continue; } let span = tcx.def_span(field.did); - let cause = ObligationCause { span, ..ObligationCause::dummy() }; + let cause = ObligationCause::dummy_with_span(span); let ctx = traits::FulfillmentContext::new(); match traits::fully_normalize(&infcx, ctx, cause, param_env, &ty) { Ok(ty) => { diff --git a/src/librustc_trait_selection/traits/wf.rs b/src/librustc_trait_selection/traits/wf.rs index 5024392a0f9..90a9b876d8d 100644 --- a/src/librustc_trait_selection/traits/wf.rs +++ b/src/librustc_trait_selection/traits/wf.rs @@ -205,7 +205,7 @@ fn extend_cause_with_original_assoc_item_obligation<'tcx>( if let Some(impl_item_span) = items.iter().find(|item| item.ident == trait_assoc_item.ident).map(fix_span) { - cause.span = impl_item_span; + cause.make_mut().span = impl_item_span; } } } @@ -222,7 +222,7 @@ fn extend_cause_with_original_assoc_item_obligation<'tcx>( items.iter().find(|i| i.ident == trait_assoc_item.ident).map(fix_span) }) { - cause.span = impl_item_span; + cause.make_mut().span = impl_item_span; } } } @@ -273,7 +273,8 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> { parent_trait_ref, parent_code: Rc::new(obligation.cause.code.clone()), }; - cause.code = traits::ObligationCauseCode::DerivedObligation(derived_cause); + cause.make_mut().code = + traits::ObligationCauseCode::DerivedObligation(derived_cause); } extend_cause_with_original_assoc_item_obligation( tcx, diff --git a/src/librustc_typeck/check/compare_method.rs b/src/librustc_typeck/check/compare_method.rs index 29cd9681295..f5444ed4039 100644 --- a/src/librustc_typeck/check/compare_method.rs +++ b/src/librustc_typeck/check/compare_method.rs @@ -78,15 +78,16 @@ fn compare_predicate_entailment<'tcx>( // `regionck_item` expects. let impl_m_hir_id = tcx.hir().as_local_hir_id(impl_m.def_id.expect_local()); - let cause = ObligationCause { - span: impl_m_span, - body_id: impl_m_hir_id, - code: ObligationCauseCode::CompareImplMethodObligation { + // We sometimes modify the span further down. + let mut cause = ObligationCause::new( + impl_m_span, + impl_m_hir_id, + ObligationCauseCode::CompareImplMethodObligation { item_name: impl_m.ident.name, impl_item_def_id: impl_m.def_id, trait_item_def_id: trait_m.def_id, }, - }; + ); // This code is best explained by example. Consider a trait: // @@ -280,7 +281,7 @@ fn compare_predicate_entailment<'tcx>( &infcx, param_env, &terr, &cause, impl_m, impl_sig, trait_m, trait_sig, ); - let cause = ObligationCause { span: impl_err_span, ..cause }; + cause.make_mut().span = impl_err_span; let mut diag = struct_span_err!( tcx.sess, @@ -965,8 +966,11 @@ crate fn compare_const_impl<'tcx>( // Compute placeholder form of impl and trait const tys. let impl_ty = tcx.type_of(impl_c.def_id); let trait_ty = tcx.type_of(trait_c.def_id).subst(tcx, trait_to_impl_substs); - let mut cause = ObligationCause::misc(impl_c_span, impl_c_hir_id); - cause.code = ObligationCauseCode::CompareImplConstObligation; + let mut cause = ObligationCause::new( + impl_c_span, + impl_c_hir_id, + ObligationCauseCode::CompareImplConstObligation, + ); // There is no "body" here, so just pass dummy id. let impl_ty = @@ -992,7 +996,7 @@ crate fn compare_const_impl<'tcx>( // Locate the Span containing just the type of the offending impl match tcx.hir().expect_impl_item(impl_c_hir_id).kind { - ImplItemKind::Const(ref ty, _) => cause.span = ty.span, + ImplItemKind::Const(ref ty, _) => cause.make_mut().span = ty.span, _ => bug!("{:?} is not a impl const", impl_c), } @@ -1095,15 +1099,15 @@ fn compare_type_predicate_entailment( // `ObligationCause` (and the `FnCtxt`). This is what // `regionck_item` expects. let impl_ty_hir_id = tcx.hir().as_local_hir_id(impl_ty.def_id.expect_local()); - let cause = ObligationCause { - span: impl_ty_span, - body_id: impl_ty_hir_id, - code: ObligationCauseCode::CompareImplTypeObligation { + let cause = ObligationCause::new( + impl_ty_span, + impl_ty_hir_id, + ObligationCauseCode::CompareImplTypeObligation { item_name: impl_ty.ident.name, impl_item_def_id: impl_ty.def_id, trait_item_def_id: trait_ty.def_id, }, - }; + ); debug!("compare_type_predicate_entailment: trait_to_impl_substs={:?}", trait_to_impl_substs); diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs index ba4bca8cd99..ee5e68ae653 100644 --- a/src/librustc_typeck/check/mod.rs +++ b/src/librustc_typeck/check/mod.rs @@ -4208,7 +4208,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { if let (Some(ref_in), None) = (referenced_in.pop(), referenced_in.pop()) { // We make sure that only *one* argument matches the obligation failure // and we assign the obligation's span to its expression's. - error.obligation.cause.span = args[ref_in].span; + error.obligation.cause.make_mut().span = args[ref_in].span; error.points_at_arg_span = true; } } @@ -4251,7 +4251,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { let ty = AstConv::ast_ty_to_ty(self, hir_ty); let ty = self.resolve_vars_if_possible(&ty); if ty == predicate.skip_binder().self_ty() { - error.obligation.cause.span = hir_ty.span; + error.obligation.cause.make_mut().span = hir_ty.span; } } } @@ -5678,7 +5678,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { { // This makes the error point at the bound, but we want to point at the argument if let Some(span) = spans.get(i) { - obligation.cause.code = traits::BindingObligation(def_id, *span); + obligation.cause.make_mut().code = traits::BindingObligation(def_id, *span); } self.register_predicate(obligation); } |