From 8f5deb4ff2e38896599866b1a33e1fffb0b7304a Mon Sep 17 00:00:00 2001 From: Lukas Wirth Date: Fri, 10 Feb 2023 14:34:58 +0100 Subject: [PATCH] Remove a few allocations in hir-ty::utils --- crates/hir-ty/src/display.rs | 2 +- crates/hir-ty/src/lower.rs | 6 +- crates/hir-ty/src/utils.rs | 181 ++++++++++++++++++----------------- 3 files changed, 96 insertions(+), 93 deletions(-) diff --git a/crates/hir-ty/src/display.rs b/crates/hir-ty/src/display.rs index 462c9b4575..5fcbdf34f3 100644 --- a/crates/hir-ty/src/display.rs +++ b/crates/hir-ty/src/display.rs @@ -927,7 +927,7 @@ impl HirDisplay for CallableSig { } } -fn fn_traits(db: &dyn DefDatabase, trait_: TraitId) -> impl Iterator { +fn fn_traits(db: &dyn DefDatabase, trait_: TraitId) -> impl Iterator + '_ { let krate = trait_.lookup(db).container.krate(); utils::fn_traits(db, krate) } diff --git a/crates/hir-ty/src/lower.rs b/crates/hir-ty/src/lower.rs index 86abe1af68..7cce13a793 100644 --- a/crates/hir-ty/src/lower.rs +++ b/crates/hir-ty/src/lower.rs @@ -1235,7 +1235,7 @@ fn named_associated_type_shorthand_candidates( mut cb: impl FnMut(&Name, &TraitRef, TypeAliasId) -> Option, ) -> Option { let mut search = |t| { - for t in all_super_trait_refs(db, t) { + all_super_trait_refs(db, t, |t| { let data = db.trait_data(t.hir_trait_id()); for (name, assoc_id) in &data.items { @@ -1245,8 +1245,8 @@ fn named_associated_type_shorthand_candidates( } } } - } - None + None + }) }; match res { diff --git a/crates/hir-ty/src/utils.rs b/crates/hir-ty/src/utils.rs index 396cba89b6..70d2d5efa6 100644 --- a/crates/hir-ty/src/utils.rs +++ b/crates/hir-ty/src/utils.rs @@ -27,23 +27,84 @@ use crate::{ db::HirDatabase, ChalkTraitId, Interner, Substitution, TraitRef, TraitRefExt, WhereClause, }; -pub(crate) fn fn_traits(db: &dyn DefDatabase, krate: CrateId) -> impl Iterator { - [ - db.lang_item(krate, LangItem::Fn), - db.lang_item(krate, LangItem::FnMut), - db.lang_item(krate, LangItem::FnOnce), - ] - .into_iter() - .flatten() - .flat_map(|it| it.as_trait()) +pub(crate) fn fn_traits( + db: &dyn DefDatabase, + krate: CrateId, +) -> impl Iterator + '_ { + [LangItem::Fn, LangItem::FnMut, LangItem::FnOnce] + .into_iter() + .filter_map(move |lang| db.lang_item(krate, lang)) + .flat_map(|it| it.as_trait()) } -fn direct_super_traits(db: &dyn DefDatabase, trait_: TraitId) -> SmallVec<[TraitId; 4]> { +/// Returns an iterator over the whole super trait hierarchy (including the +/// trait itself). +pub fn all_super_traits(db: &dyn DefDatabase, trait_: TraitId) -> SmallVec<[TraitId; 4]> { + // we need to take care a bit here to avoid infinite loops in case of cycles + // (i.e. if we have `trait A: B; trait B: A;`) + + let mut result = smallvec![trait_]; + let mut i = 0; + while let Some(&t) = result.get(i) { + // yeah this is quadratic, but trait hierarchies should be flat + // enough that this doesn't matter + direct_super_traits(db, t, |tt| { + if !result.contains(&tt) { + result.push(tt); + } + }); + i += 1; + } + result +} + +/// Given a trait ref (`Self: Trait`), builds all the implied trait refs for +/// super traits. The original trait ref will be included. So the difference to +/// `all_super_traits` is that we keep track of type parameters; for example if +/// we have `Self: Trait` and `Trait: OtherTrait` we'll get +/// `Self: OtherTrait`. +pub(super) fn all_super_trait_refs( + db: &dyn HirDatabase, + trait_ref: TraitRef, + cb: impl FnMut(TraitRef) -> Option, +) -> Option { + let seen = iter::once(trait_ref.trait_id).collect(); + let mut stack = Vec::new(); + stack.push(trait_ref); + SuperTraits { db, seen, stack }.find_map(cb) +} + +struct SuperTraits<'a> { + db: &'a dyn HirDatabase, + stack: Vec, + seen: FxHashSet, +} + +impl<'a> SuperTraits<'a> { + fn elaborate(&mut self, trait_ref: &TraitRef) { + direct_super_trait_refs(self.db, trait_ref, |trait_ref| { + if !self.seen.contains(&trait_ref.trait_id) { + self.stack.push(trait_ref); + } + }); + } +} + +impl<'a> Iterator for SuperTraits<'a> { + type Item = TraitRef; + + fn next(&mut self) -> Option { + if let Some(next) = self.stack.pop() { + self.elaborate(&next); + Some(next) + } else { + None + } + } +} + +fn direct_super_traits(db: &dyn DefDatabase, trait_: TraitId, cb: impl FnMut(TraitId)) { let resolver = trait_.resolver(db); - // returning the iterator directly doesn't easily work because of - // lifetime problems, but since there usually shouldn't be more than a - // few direct traits this should be fine (we could even use some kind of - // SmallVec if performance is a concern) let generic_params = db.generic_params(trait_.into()); let trait_self = generic_params.find_trait_self_param(); generic_params @@ -73,18 +134,14 @@ fn direct_super_traits(db: &dyn DefDatabase, trait_: TraitId) -> SmallVec<[Trait Some(TypeNs::TraitId(t)) => Some(t), _ => None, }) - .collect() + .for_each(cb); } -fn direct_super_trait_refs(db: &dyn HirDatabase, trait_ref: &TraitRef) -> Vec { - // returning the iterator directly doesn't easily work because of - // lifetime problems, but since there usually shouldn't be more than a - // few direct traits this should be fine (we could even use some kind of - // SmallVec if performance is a concern) +fn direct_super_trait_refs(db: &dyn HirDatabase, trait_ref: &TraitRef, cb: impl FnMut(TraitRef)) { let generic_params = db.generic_params(trait_ref.hir_trait_id().into()); let trait_self = match generic_params.find_trait_self_param() { Some(p) => TypeOrConstParamId { parent: trait_ref.hir_trait_id().into(), local_id: p }, - None => return Vec::new(), + None => return, }; db.generic_predicates_for_param(trait_self.parent, trait_self, None) .iter() @@ -100,64 +157,7 @@ fn direct_super_trait_refs(db: &dyn HirDatabase, trait_ref: &TraitRef) -> Vec SmallVec<[TraitId; 4]> { - // we need to take care a bit here to avoid infinite loops in case of cycles - // (i.e. if we have `trait A: B; trait B: A;`) - - let mut result = smallvec![trait_]; - let mut i = 0; - while let Some(&t) = result.get(i) { - // yeah this is quadratic, but trait hierarchies should be flat - // enough that this doesn't matter - for tt in direct_super_traits(db, t) { - if !result.contains(&tt) { - result.push(tt); - } - } - i += 1; - } - result -} - -/// Given a trait ref (`Self: Trait`), builds all the implied trait refs for -/// super traits. The original trait ref will be included. So the difference to -/// `all_super_traits` is that we keep track of type parameters; for example if -/// we have `Self: Trait` and `Trait: OtherTrait` we'll get -/// `Self: OtherTrait`. -pub(super) fn all_super_trait_refs(db: &dyn HirDatabase, trait_ref: TraitRef) -> SuperTraits<'_> { - SuperTraits { db, seen: iter::once(trait_ref.trait_id).collect(), stack: vec![trait_ref] } -} - -pub(super) struct SuperTraits<'a> { - db: &'a dyn HirDatabase, - stack: Vec, - seen: FxHashSet, -} - -impl<'a> SuperTraits<'a> { - fn elaborate(&mut self, trait_ref: &TraitRef) { - let mut trait_refs = direct_super_trait_refs(self.db, trait_ref); - trait_refs.retain(|tr| !self.seen.contains(&tr.trait_id)); - self.stack.extend(trait_refs); - } -} - -impl<'a> Iterator for SuperTraits<'a> { - type Item = TraitRef; - - fn next(&mut self) -> Option { - if let Some(next) = self.stack.pop() { - self.elaborate(&next); - Some(next) - } else { - None - } - } + .for_each(cb); } pub(super) fn associated_type_by_name_including_super_traits( @@ -165,7 +165,7 @@ pub(super) fn associated_type_by_name_including_super_traits( trait_ref: TraitRef, name: &Name, ) -> Option<(TraitRef, TypeAliasId)> { - all_super_trait_refs(db, trait_ref).find_map(|t| { + all_super_trait_refs(db, trait_ref, |t| { let assoc_type = db.trait_data(t.hir_trait_id()).associated_type_by_name(name)?; Some((t, assoc_type)) }) @@ -238,15 +238,18 @@ impl Generics { /// (parent total, self param, type param list, const param list, impl trait) pub(crate) fn provenance_split(&self) -> (usize, usize, usize, usize, usize) { - let ty_iter = || self.params.iter().filter_map(|x| x.1.type_param()); - - let self_params = - ty_iter().filter(|p| p.provenance == TypeParamProvenance::TraitSelf).count(); - let type_params = - ty_iter().filter(|p| p.provenance == TypeParamProvenance::TypeParamList).count(); - let impl_trait_params = - ty_iter().filter(|p| p.provenance == TypeParamProvenance::ArgumentImplTrait).count(); - let const_params = self.params.iter().filter_map(|x| x.1.const_param()).count(); + let mut self_params = 0; + let mut type_params = 0; + let mut impl_trait_params = 0; + let mut const_params = 0; + self.params.iter().for_each(|(_, data)| match data { + TypeOrConstParamData::TypeParamData(p) => match p.provenance { + TypeParamProvenance::TypeParamList => type_params += 1, + TypeParamProvenance::TraitSelf => self_params += 1, + TypeParamProvenance::ArgumentImplTrait => impl_trait_params += 1, + }, + TypeOrConstParamData::ConstParamData(_) => const_params += 1, + }); let parent_len = self.parent_generics().map_or(0, Generics::len); (parent_len, self_params, type_params, const_params, impl_trait_params)