diff options
18 files changed, 68 insertions, 53 deletions
diff --git a/src/libcore/borrow.rs b/src/libcore/borrow.rs index 7e4d73d598d..ebb4bd88cf1 100644 --- a/src/libcore/borrow.rs +++ b/src/libcore/borrow.rs @@ -53,12 +53,14 @@ use option::Option; use self::Cow::*; /// A trait for borrowing data. +#[old_orphan_check] pub trait BorrowFrom<Sized? Owned> for Sized? { /// Immutably borrow from an owned value. fn borrow_from(owned: &Owned) -> &Self; } /// A trait for mutably borrowing data. +#[old_orphan_check] pub trait BorrowFromMut<Sized? Owned> for Sized? : BorrowFrom<Owned> { /// Mutably borrow from an owned value. fn borrow_from_mut(owned: &mut Owned) -> &mut Self; @@ -91,6 +93,7 @@ impl<'a, T, Sized? B> BorrowFrom<Cow<'a, T, B>> for B where B: ToOwned<T> { } /// Trait for moving into a `Cow` +#[old_orphan_check] pub trait IntoCow<'a, T, Sized? B> { /// Moves `self` into `Cow` fn into_cow(self) -> Cow<'a, T, B>; @@ -103,6 +106,7 @@ impl<'a, T, Sized? B> IntoCow<'a, T, B> for Cow<'a, T, B> where B: ToOwned<T> { } /// A generalization of Clone to borrowed data. +#[old_orphan_check] pub trait ToOwned<Owned> for Sized?: BorrowFrom<Owned> { /// Create owned data from borrowed data, usually by copying. fn to_owned(&self) -> Owned; diff --git a/src/libcore/cmp.rs b/src/libcore/cmp.rs index 13f9f5ccee9..90ff174c2bd 100644 --- a/src/libcore/cmp.rs +++ b/src/libcore/cmp.rs @@ -69,6 +69,7 @@ use option::Option::{self, Some, None}; /// only if `a != b`. #[lang="eq"] #[stable] +#[old_orphan_check] pub trait PartialEq<Sized? Rhs = Self> for Sized? { /// This method tests for `self` and `other` values to be equal, and is used by `==`. #[stable] diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs index 8f03f882128..cf5ca5956f4 100644 --- a/src/librustc/lint/builtin.rs +++ b/src/librustc/lint/builtin.rs @@ -670,6 +670,9 @@ impl LintPass for UnusedAttributes { "must_use", "stable", "unstable", + + // FIXME: #19470 this shouldn't be needed forever + "old_orphan_check", ]; static CRATE_ATTRS: &'static [&'static str] = &[ diff --git a/src/librustc/middle/traits/coherence.rs b/src/librustc/middle/traits/coherence.rs index e6805cddae0..96b94ab298a 100644 --- a/src/librustc/middle/traits/coherence.rs +++ b/src/librustc/middle/traits/coherence.rs @@ -14,7 +14,7 @@ use super::SelectionContext; use super::{Obligation, ObligationCause}; use super::util; -use middle::subst::Subst; +use middle::subst::{Subst}; use middle::ty::{self, Ty}; use middle::infer::InferCtxt; use std::collections::HashSet; @@ -53,20 +53,20 @@ pub fn impl_can_satisfy(infcx: &InferCtxt, } #[allow(missing_copy_implementations)] -pub enum OrphanCheckErr { +pub enum OrphanCheckErr<'tcx> { NoLocalInputType, - UncoveredTypeParameter(ty::ParamTy), + UncoveredTy(Ty<'tcx>), } /// Checks the coherence orphan rules. `impl_def_id` should be the /// def-id of a trait impl. To pass, either the trait must be local, or else /// two conditions must be satisfied: /// -/// 1. At least one of the input types must involve a local type. -/// 2. All type parameters must be covered by a local type. -pub fn orphan_check(tcx: &ty::ctxt, - impl_def_id: ast::DefId) - -> Result<(), OrphanCheckErr> +/// 1. All type parameters in `Self` must be "covered" by some local type constructor. +/// 2. Some local type must appear in `Self`. +pub fn orphan_check<'tcx>(tcx: &ty::ctxt<'tcx>, + impl_def_id: ast::DefId) + -> Result<(), OrphanCheckErr<'tcx>> { debug!("impl_is_local({})", impl_def_id.repr(tcx)); @@ -82,31 +82,21 @@ pub fn orphan_check(tcx: &ty::ctxt, return Ok(()); } - // Check condition 1: at least one type must be local. - if !trait_ref.input_types().iter().any(|&t| ty_reaches_local(tcx, t)) { - return Err(OrphanCheckErr::NoLocalInputType); + // Otherwise, check that (1) all type parameters are covered. + let covered_params = type_parameters_covered_by_ty(tcx, trait_ref.self_ty()); + let all_params = type_parameters_reachable_from_ty(trait_ref.self_ty()); + for ¶m in all_params.difference(&covered_params) { + return Err(OrphanCheckErr::UncoveredTy(param)); } - // Check condition 2: type parameters must be "covered" by a local type. - let covered_params: HashSet<_> = - trait_ref.input_types().iter() - .flat_map(|&t| type_parameters_covered_by_ty(tcx, t).into_iter()) - .collect(); - let all_params: HashSet<_> = - trait_ref.input_types().iter() - .flat_map(|&t| type_parameters_reachable_from_ty(t).into_iter()) - .collect(); - for ¶m in all_params.difference(&covered_params) { - return Err(OrphanCheckErr::UncoveredTypeParameter(param)); + // And (2) some local type appears. + if !trait_ref.self_ty().walk().any(|t| ty_is_local_constructor(tcx, t)) { + return Err(OrphanCheckErr::NoLocalInputType); } return Ok(()); } -fn ty_reaches_local<'tcx>(tcx: &ty::ctxt<'tcx>, ty: Ty<'tcx>) -> bool { - ty.walk().any(|t| ty_is_local_constructor(tcx, t)) -} - fn ty_is_local_constructor<'tcx>(tcx: &ty::ctxt<'tcx>, ty: Ty<'tcx>) -> bool { debug!("ty_is_local_constructor({})", ty.repr(tcx)); @@ -154,8 +144,8 @@ fn ty_is_local_constructor<'tcx>(tcx: &ty::ctxt<'tcx>, ty: Ty<'tcx>) -> bool { } fn type_parameters_covered_by_ty<'tcx>(tcx: &ty::ctxt<'tcx>, - ty: Ty<'tcx>) - -> HashSet<ty::ParamTy> + ty: Ty<'tcx>) + -> HashSet<Ty<'tcx>> { if ty_is_local_constructor(tcx, ty) { type_parameters_reachable_from_ty(ty) @@ -165,14 +155,14 @@ fn type_parameters_covered_by_ty<'tcx>(tcx: &ty::ctxt<'tcx>, } /// All type parameters reachable from `ty` -fn type_parameters_reachable_from_ty<'tcx>(ty: Ty<'tcx>) -> HashSet<ty::ParamTy> { +fn type_parameters_reachable_from_ty<'tcx>(ty: Ty<'tcx>) -> HashSet<Ty<'tcx>> { ty.walk() - .filter_map(|t| { + .filter(|&t| { match t.sty { - ty::ty_param(ref param_ty) => Some(param_ty.clone()), - _ => None, + // FIXME(#20590) straighten story about projection types + ty::ty_projection(..) | ty::ty_param(..) => true, + _ => false, } }) .collect() } - diff --git a/src/librustc_typeck/check/callee.rs b/src/librustc_typeck/check/callee.rs index 153c6463fbe..0bc76e1baab 100644 --- a/src/librustc_typeck/check/callee.rs +++ b/src/librustc_typeck/check/callee.rs @@ -22,7 +22,7 @@ use super::TupleArgumentsFlag; use super::write_call; use middle::infer; -use middle::ty::{mod, Ty}; +use middle::ty::{self, Ty}; use syntax::ast; use syntax::codemap::Span; use syntax::parse::token; diff --git a/src/librustc_typeck/coherence/orphan.rs b/src/librustc_typeck/coherence/orphan.rs index 1da49799712..dc22fd597e6 100644 --- a/src/librustc_typeck/coherence/orphan.rs +++ b/src/librustc_typeck/coherence/orphan.rs @@ -72,20 +72,30 @@ impl<'cx, 'tcx,'v> visit::Visitor<'v> for OrphanChecker<'cx, 'tcx> { ast::ItemImpl(_, _, Some(_), _, _) => { // "Trait" impl debug!("coherence2::orphan check: trait impl {}", item.repr(self.tcx)); + let trait_def_id = ty::impl_trait_ref(self.tcx, def_id).unwrap().def_id; match traits::orphan_check(self.tcx, def_id) { Ok(()) => { } Err(traits::OrphanCheckErr::NoLocalInputType) => { - span_err!(self.tcx.sess, item.span, E0117, - "cannot provide an extension implementation \ - where both trait and type are not defined in this crate"); + if !ty::has_attr(self.tcx, trait_def_id, "old_orphan_check") { + let self_ty = ty::lookup_item_type(self.tcx, def_id).ty; + span_err!( + self.tcx.sess, item.span, E0117, + "the type `{}` does not reference any \ + types defined in this crate; \ + only traits defined in the current crate can be \ + implemented for arbitrary types", + self_ty.user_string(self.tcx)); + } } - Err(traits::OrphanCheckErr::UncoveredTypeParameter(param_ty)) => { - if !self.tcx.sess.features.borrow().old_orphan_check { + Err(traits::OrphanCheckErr::UncoveredTy(param_ty)) => { + if !ty::has_attr(self.tcx, trait_def_id, "old_orphan_check") { self.tcx.sess.span_err( item.span, - format!("type parameter `{}` must also appear as a type parameter \ - of some type defined within this crate", - param_ty.user_string(self.tcx)).as_slice()); + format!( + "type parameter `{}` is not constrained by any local type; \ + only traits defined in the current crate can be implemented \ + for a type parameter", + param_ty.user_string(self.tcx)).as_slice()); self.tcx.sess.span_note( item.span, format!("for a limited time, you can add \ diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs index f75873ac1c0..f08c40ff099 100644 --- a/src/libsyntax/feature_gate.rs +++ b/src/libsyntax/feature_gate.rs @@ -301,6 +301,14 @@ impl<'a, 'v> Visitor<'v> for PostExpansionVisitor<'a> { removed in the future"); } + if attr::contains_name(i.attrs[], + "old_orphan_check") { + self.gate_feature( + "old_orphan_check", + i.span, + "the new orphan check rules will eventually be strictly enforced"); + } + for item in items.iter() { match *item { ast::MethodImplItem(_) => {} diff --git a/src/test/compile-fail/coherence-all-remote.rs b/src/test/compile-fail/coherence-all-remote.rs index 67d96aa95a6..d88b8751ea7 100644 --- a/src/test/compile-fail/coherence-all-remote.rs +++ b/src/test/compile-fail/coherence-all-remote.rs @@ -14,6 +14,6 @@ extern crate "coherence-lib" as lib; use lib::Remote; impl<T> Remote for int { } -//~^ ERROR cannot provide an extension implementation +//~^ ERROR E0117 fn main() { } diff --git a/src/test/run-pass/coherence-bigint-int.rs b/src/test/compile-fail/coherence-bigint-int.rs index 1e90453980f..b4917d0c29f 100644 --- a/src/test/run-pass/coherence-bigint-int.rs +++ b/src/test/compile-fail/coherence-bigint-int.rs @@ -15,6 +15,6 @@ use lib::Remote1; pub struct BigInt; -impl Remote1<BigInt> for int { } +impl Remote1<BigInt> for int { } //~ ERROR E0117 fn main() { } diff --git a/src/test/compile-fail/coherence-bigint-param.rs b/src/test/compile-fail/coherence-bigint-param.rs index a04dfd36c98..b8e48436a41 100644 --- a/src/test/compile-fail/coherence-bigint-param.rs +++ b/src/test/compile-fail/coherence-bigint-param.rs @@ -16,6 +16,6 @@ use lib::Remote1; pub struct BigInt; impl<T> Remote1<BigInt> for T { } -//~^ ERROR type parameter `T` must also appear +//~^ ERROR type parameter `T` is not constrained fn main() { } diff --git a/src/test/run-pass/coherence-bigint-vecint.rs b/src/test/compile-fail/coherence-bigint-vecint.rs index b100455eb33..de4e656110f 100644 --- a/src/test/run-pass/coherence-bigint-vecint.rs +++ b/src/test/compile-fail/coherence-bigint-vecint.rs @@ -15,6 +15,6 @@ use lib::Remote1; pub struct BigInt; -impl Remote1<BigInt> for Vec<int> { } +impl Remote1<BigInt> for Vec<int> { } //~ ERROR E0117 fn main() { } diff --git a/src/test/compile-fail/coherence-cross-crate-conflict.rs b/src/test/compile-fail/coherence-cross-crate-conflict.rs index 99446be43ac..8bdd5c58f31 100644 --- a/src/test/compile-fail/coherence-cross-crate-conflict.rs +++ b/src/test/compile-fail/coherence-cross-crate-conflict.rs @@ -16,7 +16,7 @@ extern crate trait_impl_conflict; use trait_impl_conflict::Foo; impl<A> Foo for A { - //~^ ERROR E0117 + //~^ ERROR type parameter `A` is not constrained //~^^ ERROR E0119 } diff --git a/src/test/compile-fail/coherence-lone-type-parameter.rs b/src/test/compile-fail/coherence-lone-type-parameter.rs index 0223dacd8ec..917438722de 100644 --- a/src/test/compile-fail/coherence-lone-type-parameter.rs +++ b/src/test/compile-fail/coherence-lone-type-parameter.rs @@ -13,6 +13,6 @@ extern crate "coherence-lib" as lib; use lib::Remote; -impl<T> Remote for T { } //~ ERROR E0117 +impl<T> Remote for T { } //~ ERROR type parameter `T` is not constrained fn main() { } diff --git a/src/test/compile-fail/coherence-orphan.rs b/src/test/compile-fail/coherence-orphan.rs index c44b0da5b15..30a382c143d 100644 --- a/src/test/compile-fail/coherence-orphan.rs +++ b/src/test/compile-fail/coherence-orphan.rs @@ -18,7 +18,7 @@ struct TheType; impl TheTrait<uint> for int { } //~ ERROR E0117 -impl TheTrait<TheType> for int { } +impl TheTrait<TheType> for int { } //~ ERROR E0117 impl TheTrait<int> for TheType { } diff --git a/src/test/compile-fail/coherence-overlapping-pairs.rs b/src/test/compile-fail/coherence-overlapping-pairs.rs index d42bd529b66..9354e66af0d 100644 --- a/src/test/compile-fail/coherence-overlapping-pairs.rs +++ b/src/test/compile-fail/coherence-overlapping-pairs.rs @@ -16,6 +16,6 @@ use lib::Remote; struct Foo; impl<T> Remote for lib::Pair<T,Foo> { } -//~^ ERROR type parameter `T` must also appear +//~^ ERROR type parameter `T` is not constrained fn main() { } diff --git a/src/test/compile-fail/coherence-pair-covered-uncovered.rs b/src/test/compile-fail/coherence-pair-covered-uncovered.rs index 09895ec11db..92a07b35852 100644 --- a/src/test/compile-fail/coherence-pair-covered-uncovered.rs +++ b/src/test/compile-fail/coherence-pair-covered-uncovered.rs @@ -16,6 +16,6 @@ use lib::{Remote, Pair}; struct Local<T>(T); impl<T,U> Remote for Pair<T,Local<U>> { } -//~^ ERROR type parameter `T` must also appear +//~^ ERROR type parameter `T` is not constrained fn main() { } diff --git a/src/test/compile-fail/drop-on-non-struct.rs b/src/test/compile-fail/drop-on-non-struct.rs index 8304afa1141..238700254b8 100644 --- a/src/test/compile-fail/drop-on-non-struct.rs +++ b/src/test/compile-fail/drop-on-non-struct.rs @@ -10,7 +10,7 @@ impl Drop for int { //~^ ERROR the Drop trait may only be implemented on structures - //~^^ ERROR cannot provide an extension implementation + //~^^ ERROR E0117 fn drop(&mut self) { println!("kaboom"); } diff --git a/src/test/compile-fail/coherence-iterator-vec-any-elem.rs b/src/test/run-pass/coherence-iterator-vec-any-elem.rs index 2ed7a6db7ae..6dc2ff4588b 100644 --- a/src/test/compile-fail/coherence-iterator-vec-any-elem.rs +++ b/src/test/run-pass/coherence-iterator-vec-any-elem.rs @@ -16,6 +16,5 @@ use lib::Remote1; struct Foo<T>(T); impl<T,U> Remote1<U> for Foo<T> { } -//~^ ERROR type parameter `U` must also appear fn main() { } |