diff options
| -rw-r--r-- | Cargo.lock | 1 | ||||
| -rw-r--r-- | src/librustc/hir/mod.rs | 6 | ||||
| -rw-r--r-- | src/librustc/ich/impls_hir.rs | 21 | ||||
| -rw-r--r-- | src/librustc_data_structures/stable_hasher.rs | 10 | ||||
| -rw-r--r-- | src/librustc_resolve/Cargo.toml | 1 | ||||
| -rw-r--r-- | src/librustc_resolve/lib.rs | 39 | ||||
| -rw-r--r-- | src/librustc_typeck/check/method/mod.rs | 6 | ||||
| -rw-r--r-- | src/librustc_typeck/check/method/probe.rs | 31 | ||||
| -rw-r--r-- | src/test/ui/lint/unused_import_warning_issue_45268.rs | 48 | ||||
| -rw-r--r-- | src/test/ui/lint/unused_import_warning_issue_45268.stderr | 12 |
10 files changed, 127 insertions, 48 deletions
diff --git a/Cargo.lock b/Cargo.lock index 7823c377b2a..ffa33393c30 100644 --- a/Cargo.lock +++ b/Cargo.lock @@ -2957,6 +2957,7 @@ dependencies = [ "rustc_data_structures 0.0.0", "rustc_errors 0.0.0", "rustc_metadata 0.0.0", + "smallvec 0.6.7 (registry+https://github.com/rust-lang/crates.io-index)", "syntax 0.0.0", "syntax_pos 0.0.0", ] diff --git a/src/librustc/hir/mod.rs b/src/librustc/hir/mod.rs index ae7358df9d8..9ce300ce048 100644 --- a/src/librustc/hir/mod.rs +++ b/src/librustc/hir/mod.rs @@ -37,6 +37,7 @@ use rustc_macros::HashStable; use serialize::{self, Encoder, Encodable, Decoder, Decodable}; use std::collections::{BTreeSet, BTreeMap}; use std::fmt; +use smallvec::SmallVec; /// HIR doesn't commit to a concrete storage type and has its own alias for a vector. /// It can be `Vec`, `P<[T]>` or potentially `Box<[T]>`, or some other container with similar @@ -2505,10 +2506,13 @@ pub type FreevarMap = NodeMap<Vec<Freevar<ast::NodeId>>>; pub type CaptureModeMap = NodeMap<CaptureClause>; + // The TraitCandidate's import_ids is empty if the trait is defined in the same module, and + // has length > 0 if the trait is found through an chain of imports, starting with the + // import/use statement in the scope where the trait is used. #[derive(Clone, Debug)] pub struct TraitCandidate { pub def_id: DefId, - pub import_id: Option<NodeId>, + pub import_ids: SmallVec<[NodeId; 1]>, } // Trait method resolution diff --git a/src/librustc/ich/impls_hir.rs b/src/librustc/ich/impls_hir.rs index 65795d2b136..5b2a1e783c0 100644 --- a/src/librustc/ich/impls_hir.rs +++ b/src/librustc/ich/impls_hir.rs @@ -7,6 +7,7 @@ use crate::hir::def_id::{DefId, LocalDefId, CrateNum, CRATE_DEF_INDEX}; use crate::ich::{StableHashingContext, NodeIdHashingMode, Fingerprint}; use rustc_data_structures::stable_hasher::{HashStable, ToStableHashKey, StableHasher, StableHasherResult}; +use smallvec::SmallVec; use std::mem; use syntax::ast; use syntax::attr; @@ -393,30 +394,30 @@ impl<'a> HashStable<StableHashingContext<'a>> for hir::TraitCandidate { hcx.with_node_id_hashing_mode(NodeIdHashingMode::HashDefPath, |hcx| { let hir::TraitCandidate { def_id, - import_id, - } = *self; + import_ids, + } = self; def_id.hash_stable(hcx, hasher); - import_id.hash_stable(hcx, hasher); + import_ids.hash_stable(hcx, hasher); }); } } impl<'a> ToStableHashKey<StableHashingContext<'a>> for hir::TraitCandidate { - type KeyType = (DefPathHash, Option<(DefPathHash, hir::ItemLocalId)>); + type KeyType = (DefPathHash, SmallVec<[(DefPathHash, hir::ItemLocalId); 1]>); fn to_stable_hash_key(&self, hcx: &StableHashingContext<'a>) -> Self::KeyType { let hir::TraitCandidate { def_id, - import_id, - } = *self; + import_ids, + } = self; - let import_id = import_id.map(|node_id| hcx.node_to_hir_id(node_id)) - .map(|hir_id| (hcx.local_def_path_hash(hir_id.owner), - hir_id.local_id)); - (hcx.def_path_hash(def_id), import_id) + let import_keys = import_ids.iter().map(|node_id| hcx.node_to_hir_id(*node_id)) + .map(|hir_id| (hcx.local_def_path_hash(hir_id.owner), + hir_id.local_id)).collect(); + (hcx.def_path_hash(*def_id), import_keys) } } diff --git a/src/librustc_data_structures/stable_hasher.rs b/src/librustc_data_structures/stable_hasher.rs index 19343a9250d..fa573907d4c 100644 --- a/src/librustc_data_structures/stable_hasher.rs +++ b/src/librustc_data_structures/stable_hasher.rs @@ -1,6 +1,7 @@ use std::hash::{Hash, Hasher, BuildHasher}; use std::marker::PhantomData; use std::mem; +use smallvec::SmallVec; use crate::sip128::SipHasher128; use crate::indexed_vec; use crate::bit_set; @@ -318,6 +319,15 @@ impl<T: HashStable<CTX>, CTX> HashStable<CTX> for Vec<T> { } } +impl<A, CTX> HashStable<CTX> for SmallVec<[A; 1]> where A: HashStable<CTX> { + #[inline] + fn hash_stable<W: StableHasherResult>(&self, + ctx: &mut CTX, + hasher: &mut StableHasher<W>) { + (&self[..]).hash_stable(ctx, hasher); + } +} + impl<T: ?Sized + HashStable<CTX>, CTX> HashStable<CTX> for Box<T> { #[inline] fn hash_stable<W: StableHasherResult>(&self, diff --git a/src/librustc_resolve/Cargo.toml b/src/librustc_resolve/Cargo.toml index 836b4ad38ca..968a45e241e 100644 --- a/src/librustc_resolve/Cargo.toml +++ b/src/librustc_resolve/Cargo.toml @@ -20,3 +20,4 @@ errors = { path = "../librustc_errors", package = "rustc_errors" } syntax_pos = { path = "../libsyntax_pos" } rustc_data_structures = { path = "../librustc_data_structures" } rustc_metadata = { path = "../librustc_metadata" } +smallvec = { version = "0.6.7", features = ["union", "may_dangle"] } diff --git a/src/librustc_resolve/lib.rs b/src/librustc_resolve/lib.rs index e0892f98d31..c439ad9c315 100644 --- a/src/librustc_resolve/lib.rs +++ b/src/librustc_resolve/lib.rs @@ -17,6 +17,7 @@ pub use rustc::hir::def::{Namespace, PerNS}; use GenericParameters::*; use RibKind::*; +use smallvec::smallvec; use rustc::hir::map::{Definitions, DefCollector}; use rustc::hir::{self, PrimTy, Bool, Char, Float, Int, Uint, Str}; @@ -66,6 +67,7 @@ use std::collections::BTreeSet; use std::mem::replace; use rustc_data_structures::ptr_key::PtrKey; use rustc_data_structures::sync::Lrc; +use smallvec::SmallVec; use diagnostics::{find_span_of_binding_until_next_binding, extend_span_to_previous_binding}; use resolve_imports::{ImportDirective, ImportDirectiveSubclass, NameResolution, ImportResolver}; @@ -4582,7 +4584,7 @@ impl<'a> Resolver<'a> { module.span, ).is_ok() { let def_id = module.def_id().unwrap(); - found_traits.push(TraitCandidate { def_id: def_id, import_id: None }); + found_traits.push(TraitCandidate { def_id: def_id, import_ids: smallvec![] }); } } @@ -4641,37 +4643,34 @@ impl<'a> Resolver<'a> { false, module.span, ).is_ok() { - let import_id = match binding.kind { - NameBindingKind::Import { directive, .. } => { - self.maybe_unused_trait_imports.insert(directive.id); - self.add_to_glob_map(&directive, trait_name); - Some(directive.id) - } - _ => None, - }; + let import_ids = self.find_transitive_imports(&binding.kind, trait_name); let trait_def_id = module.def_id().unwrap(); - found_traits.push(TraitCandidate { def_id: trait_def_id, import_id }); + found_traits.push(TraitCandidate { def_id: trait_def_id, import_ids }); } } else if let Res::Def(DefKind::TraitAlias, _) = binding.res() { // For now, just treat all trait aliases as possible candidates, since we don't // know if the ident is somewhere in the transitive bounds. - - let import_id = match binding.kind { - NameBindingKind::Import { directive, .. } => { - self.maybe_unused_trait_imports.insert(directive.id); - self.add_to_glob_map(&directive, trait_name); - Some(directive.id) - } - _ => None, - }; + let import_ids = self.find_transitive_imports(&binding.kind, trait_name); let trait_def_id = binding.res().def_id(); - found_traits.push(TraitCandidate { def_id: trait_def_id, import_id }); + found_traits.push(TraitCandidate { def_id: trait_def_id, import_ids }); } else { bug!("candidate is not trait or trait alias?") } } } + fn find_transitive_imports(&mut self, mut kind: &NameBindingKind<'_>, + trait_name: Ident) -> SmallVec<[NodeId; 1]> { + let mut import_ids = smallvec![]; + while let NameBindingKind::Import { directive, binding, .. } = kind { + self.maybe_unused_trait_imports.insert(directive.id); + self.add_to_glob_map(&directive, trait_name); + import_ids.push(directive.id); + kind = &binding.kind; + }; + import_ids + } + fn lookup_import_candidates_from_module<FilterFn>(&mut self, lookup_ident: Ident, namespace: Namespace, diff --git a/src/librustc_typeck/check/method/mod.rs b/src/librustc_typeck/check/method/mod.rs index bbdc7df4441..a4b1687ea53 100644 --- a/src/librustc_typeck/check/method/mod.rs +++ b/src/librustc_typeck/check/method/mod.rs @@ -195,8 +195,8 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { ProbeScope::TraitsInScope )?; - if let Some(import_id) = pick.import_id { - let import_def_id = self.tcx.hir().local_def_id_from_hir_id(import_id); + for import_id in &pick.import_ids { + let import_def_id = self.tcx.hir().local_def_id_from_hir_id(*import_id); debug!("used_trait_import: {:?}", import_def_id); Lrc::get_mut(&mut self.tables.borrow_mut().used_trait_imports) .unwrap().insert(import_def_id); @@ -434,7 +434,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { let pick = self.probe_for_name(span, probe::Mode::Path, method_name, IsSuggestion(false), self_ty, expr_id, ProbeScope::TraitsInScope)?; debug!("resolve_ufcs: pick={:?}", pick); - if let Some(import_id) = pick.import_id { + for import_id in pick.import_ids { let import_def_id = tcx.hir().local_def_id_from_hir_id(import_id); debug!("resolve_ufcs: used_trait_import: {:?}", import_def_id); Lrc::get_mut(&mut self.tables.borrow_mut().used_trait_imports) diff --git a/src/librustc_typeck/check/method/probe.rs b/src/librustc_typeck/check/method/probe.rs index 8c61a127d10..314f7e97cd2 100644 --- a/src/librustc_typeck/check/method/probe.rs +++ b/src/librustc_typeck/check/method/probe.rs @@ -35,6 +35,8 @@ use std::mem; use std::ops::Deref; use std::cmp::max; +use smallvec::{smallvec, SmallVec}; + use self::CandidateKind::*; pub use self::PickKind::*; @@ -121,7 +123,7 @@ struct Candidate<'tcx> { xform_ret_ty: Option<Ty<'tcx>>, item: ty::AssociatedItem, kind: CandidateKind<'tcx>, - import_id: Option<hir::HirId>, + import_ids: SmallVec<[hir::HirId; 1]>, } #[derive(Debug)] @@ -146,7 +148,7 @@ enum ProbeResult { pub struct Pick<'tcx> { pub item: ty::AssociatedItem, pub kind: PickKind<'tcx>, - pub import_id: Option<hir::HirId>, + pub import_ids: SmallVec<[hir::HirId; 1]>, // Indicates that the source expression should be autoderef'd N times // @@ -716,7 +718,7 @@ impl<'a, 'gcx, 'tcx> ProbeContext<'a, 'gcx, 'tcx> { self.push_candidate(Candidate { xform_self_ty, xform_ret_ty, item, kind: InherentImplCandidate(impl_substs, obligations), - import_id: None + import_ids: smallvec![] }, true); } } @@ -750,7 +752,7 @@ impl<'a, 'gcx, 'tcx> ProbeContext<'a, 'gcx, 'tcx> { this.push_candidate(Candidate { xform_self_ty, xform_ret_ty, item, kind: ObjectCandidate, - import_id: None + import_ids: smallvec![] }, true); }); } @@ -799,7 +801,7 @@ impl<'a, 'gcx, 'tcx> ProbeContext<'a, 'gcx, 'tcx> { this.push_candidate(Candidate { xform_self_ty, xform_ret_ty, item, kind: WhereClauseCandidate(poly_trait_ref), - import_id: None + import_ids: smallvec![] }, true); }); } @@ -838,9 +840,10 @@ impl<'a, 'gcx, 'tcx> ProbeContext<'a, 'gcx, 'tcx> { for trait_candidate in applicable_traits.iter() { let trait_did = trait_candidate.def_id; if duplicates.insert(trait_did) { - let import_id = trait_candidate.import_id.map(|node_id| - self.fcx.tcx.hir().node_to_hir_id(node_id)); - let result = self.assemble_extension_candidates_for_trait(import_id, trait_did); + let import_ids = trait_candidate.import_ids.iter().map(|node_id| + self.fcx.tcx.hir().node_to_hir_id(*node_id)).collect(); + let result = self.assemble_extension_candidates_for_trait(import_ids, + trait_did); result?; } } @@ -852,7 +855,7 @@ impl<'a, 'gcx, 'tcx> ProbeContext<'a, 'gcx, 'tcx> { let mut duplicates = FxHashSet::default(); for trait_info in suggest::all_traits(self.tcx) { if duplicates.insert(trait_info.def_id) { - self.assemble_extension_candidates_for_trait(None, trait_info.def_id)?; + self.assemble_extension_candidates_for_trait(smallvec![], trait_info.def_id)?; } } Ok(()) @@ -890,7 +893,7 @@ impl<'a, 'gcx, 'tcx> ProbeContext<'a, 'gcx, 'tcx> { } fn assemble_extension_candidates_for_trait(&mut self, - import_id: Option<hir::HirId>, + import_ids: SmallVec<[hir::HirId; 1]>, trait_def_id: DefId) -> Result<(), MethodError<'tcx>> { debug!("assemble_extension_candidates_for_trait(trait_def_id={:?})", @@ -907,7 +910,7 @@ impl<'a, 'gcx, 'tcx> ProbeContext<'a, 'gcx, 'tcx> { let (xform_self_ty, xform_ret_ty) = this.xform_self_ty(&item, new_trait_ref.self_ty(), new_trait_ref.substs); this.push_candidate(Candidate { - xform_self_ty, xform_ret_ty, item, import_id, + xform_self_ty, xform_ret_ty, item, import_ids: import_ids.clone(), kind: TraitCandidate(new_trait_ref), }, true); }); @@ -924,7 +927,7 @@ impl<'a, 'gcx, 'tcx> ProbeContext<'a, 'gcx, 'tcx> { let (xform_self_ty, xform_ret_ty) = self.xform_self_ty(&item, trait_ref.self_ty(), trait_substs); self.push_candidate(Candidate { - xform_self_ty, xform_ret_ty, item, import_id, + xform_self_ty, xform_ret_ty, item, import_ids: import_ids.clone(), kind: TraitCandidate(trait_ref), }, false); } @@ -1413,7 +1416,7 @@ impl<'a, 'gcx, 'tcx> ProbeContext<'a, 'gcx, 'tcx> { Some(Pick { item: probes[0].0.item.clone(), kind: TraitPick, - import_id: probes[0].0.import_id, + import_ids: probes[0].0.import_ids.clone(), autoderefs: 0, autoref: None, unsize: None, @@ -1652,7 +1655,7 @@ impl<'tcx> Candidate<'tcx> { WhereClausePick(trait_ref.clone()) } }, - import_id: self.import_id, + import_ids: self.import_ids.clone(), autoderefs: 0, autoref: None, unsize: None, diff --git a/src/test/ui/lint/unused_import_warning_issue_45268.rs b/src/test/ui/lint/unused_import_warning_issue_45268.rs new file mode 100644 index 00000000000..0bd77511135 --- /dev/null +++ b/src/test/ui/lint/unused_import_warning_issue_45268.rs @@ -0,0 +1,48 @@ +// compile-pass + +#![warn(unused_imports)] // Warning explanation here, it's OK + +mod test { + pub trait A { + fn a(); + } + + impl A for () { + fn a() { } + } + + pub trait B { + fn b(self); + } + + impl B for () { + fn b(self) { } + } + + pub trait Unused { + } +} + +use test::Unused; // This is really unused, so warning is OK +use test::A; // This is used by the test2::func() through import of super::* +use test::B; // This is used by the test2::func() through import of super::* + +mod test2 { + use super::*; + pub fn func() { + let _ = <()>::a(); + let _ = ().b(); + test3::inner_func(); + } + mod test3 { + use super::*; + pub fn inner_func() { + let _ = <()>::a(); + let _ = ().b(); + } + } +} + +fn main() { + test2::func(); +} diff --git a/src/test/ui/lint/unused_import_warning_issue_45268.stderr b/src/test/ui/lint/unused_import_warning_issue_45268.stderr new file mode 100644 index 00000000000..7392e99f7ae --- /dev/null +++ b/src/test/ui/lint/unused_import_warning_issue_45268.stderr @@ -0,0 +1,12 @@ +warning: unused import: `test::Unused` + --> $DIR/unused_import_warning_issue_45268.rs:26:5 + | +LL | use test::Unused; // This is really unused, so warning is OK + | ^^^^^^^^^^^^ + | +note: lint level defined here + --> $DIR/unused_import_warning_issue_45268.rs:3:9 + | +LL | #![warn(unused_imports)] // Warning explanation here, it's OK + | ^^^^^^^^^^^^^^ + |