diff --git a/src/librustc_infer/infer/combine.rs b/src/librustc_infer/infer/combine.rs index 70a2122a9ea..4ef4ed47cb1 100644 --- a/src/librustc_infer/infer/combine.rs +++ b/src/librustc_infer/infer/combine.rs @@ -307,7 +307,7 @@ impl<'infcx, 'tcx> CombineFields<'infcx, 'tcx> { self.obligations.push(Obligation::new( self.trace.cause.clone(), self.param_env, - ty::PredicateKind::WellFormed(b_ty).to_predicate(self.infcx.tcx), + ty::PredicateKind::WellFormed(b_ty.into()).to_predicate(self.infcx.tcx), )); } diff --git a/src/librustc_infer/infer/outlives/mod.rs b/src/librustc_infer/infer/outlives/mod.rs index ad8e44a6c1d..fd3b38e9d67 100644 --- a/src/librustc_infer/infer/outlives/mod.rs +++ b/src/librustc_infer/infer/outlives/mod.rs @@ -20,8 +20,7 @@ pub fn explicit_outlives_bounds<'tcx>( | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::TypeOutlives(..) | ty::PredicateKind::ConstEvaluatable(..) - | ty::PredicateKind::ConstEquate(..) - | ty::PredicateKind::WellFormedConst(..) => None, + | ty::PredicateKind::ConstEquate(..) => None, ty::PredicateKind::RegionOutlives(ref data) => data .no_bound_vars() .map(|ty::OutlivesPredicate(r_a, r_b)| OutlivesBound::RegionSubRegion(r_b, r_a)), diff --git a/src/librustc_infer/traits/util.rs b/src/librustc_infer/traits/util.rs index 1aaa07d23cc..8081cac0067 100644 --- a/src/librustc_infer/traits/util.rs +++ b/src/librustc_infer/traits/util.rs @@ -45,8 +45,6 @@ pub fn anonymize_predicate<'tcx>( } ty::PredicateKind::ConstEquate(c1, c2) => ty::PredicateKind::ConstEquate(c1, c2), - - ty::PredicateKind::WellFormedConst(ct) => ty::PredicateKind::WellFormedConst(ct), }; if new != *kind { new.to_predicate(tcx) } else { pred } @@ -206,9 +204,6 @@ impl Elaborator<'tcx> { // Currently, we do not elaborate const-equate // predicates. } - ty::PredicateKind::WellFormedConst(..) => { - // Currently, we do not elaborate WF predicates. - } ty::PredicateKind::RegionOutlives(..) => { // Nothing to elaborate from `'a: 'b`. } diff --git a/src/librustc_lint/builtin.rs b/src/librustc_lint/builtin.rs index bde761b01c3..e17e8b7b964 100644 --- a/src/librustc_lint/builtin.rs +++ b/src/librustc_lint/builtin.rs @@ -1218,7 +1218,6 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for TrivialConstraints { Projection(..) | // Ignore bounds that a user can't type WellFormed(..) | - WellFormedConst(..) | ObjectSafe(..) | ClosureKind(..) | Subtype(..) | diff --git a/src/librustc_middle/ty/mod.rs b/src/librustc_middle/ty/mod.rs index 554553dc6b4..a34cff06bc1 100644 --- a/src/librustc_middle/ty/mod.rs +++ b/src/librustc_middle/ty/mod.rs @@ -14,7 +14,7 @@ use crate::mir::Body; use crate::mir::GeneratorLayout; use crate::traits::{self, Reveal}; use crate::ty; -use crate::ty::subst::{InternalSubsts, Subst, SubstsRef}; +use crate::ty::subst::{GenericArg, InternalSubsts, Subst, SubstsRef}; use crate::ty::util::{Discr, IntTypeExt}; use rustc_ast::ast; use rustc_attr as attr; @@ -1061,7 +1061,7 @@ pub enum PredicateKind<'tcx> { Projection(PolyProjectionPredicate<'tcx>), /// No syntax: `T` well-formed. - WellFormed(Ty<'tcx>), + WellFormed(GenericArg<'tcx>), /// Trait must be object-safe. ObjectSafe(DefId), @@ -1079,9 +1079,6 @@ pub enum PredicateKind<'tcx> { /// Constants must be equal. The first component is the const that is expected. ConstEquate(&'tcx Const<'tcx>, &'tcx Const<'tcx>), - - /// Constant must be well formed. - WellFormedConst(&'tcx Const<'tcx>), } /// The crate outlives map is computed during typeck and contains the @@ -1198,9 +1195,6 @@ impl<'tcx> Predicate<'tcx> { PredicateKind::ConstEquate(c1, c2) => { PredicateKind::ConstEquate(c1.subst(tcx, substs), c2.subst(tcx, substs)) } - PredicateKind::WellFormedConst(c) => { - PredicateKind::WellFormedConst(c.subst(tcx, substs)) - } }; if new != *kind { new.to_predicate(tcx) } else { self } @@ -1392,8 +1386,7 @@ impl<'tcx> Predicate<'tcx> { | PredicateKind::ClosureKind(..) | PredicateKind::TypeOutlives(..) | PredicateKind::ConstEvaluatable(..) - | PredicateKind::ConstEquate(..) - | PredicateKind::WellFormedConst(..) => None, + | PredicateKind::ConstEquate(..) => None, } } @@ -1408,8 +1401,7 @@ impl<'tcx> Predicate<'tcx> { | PredicateKind::ObjectSafe(..) | PredicateKind::ClosureKind(..) | PredicateKind::ConstEvaluatable(..) - | PredicateKind::ConstEquate(..) - | PredicateKind::WellFormedConst(..) => None, + | PredicateKind::ConstEquate(..) => None, } } } diff --git a/src/librustc_middle/ty/print/pretty.rs b/src/librustc_middle/ty/print/pretty.rs index 6eb11b0c942..90fb1981617 100644 --- a/src/librustc_middle/ty/print/pretty.rs +++ b/src/librustc_middle/ty/print/pretty.rs @@ -2031,7 +2031,7 @@ define_print_and_forward_display! { ty::PredicateKind::RegionOutlives(predicate) => p!(print(predicate)), ty::PredicateKind::TypeOutlives(predicate) => p!(print(predicate)), ty::PredicateKind::Projection(predicate) => p!(print(predicate)), - ty::PredicateKind::WellFormed(ty) => p!(print(ty), write(" well-formed")), + ty::PredicateKind::WellFormed(arg) => p!(print(arg), write(" well-formed")), &ty::PredicateKind::ObjectSafe(trait_def_id) => { p!(write("the trait `"), print_def_path(trait_def_id, &[]), @@ -2054,9 +2054,6 @@ define_print_and_forward_display! { print(c2), write("`")) } - ty::PredicateKind::WellFormedConst(c) => { - p!(print(c), write(" well-formed")) - } } } diff --git a/src/librustc_middle/ty/structural_impls.rs b/src/librustc_middle/ty/structural_impls.rs index 19a2e89ca41..6c1a524b7fe 100644 --- a/src/librustc_middle/ty/structural_impls.rs +++ b/src/librustc_middle/ty/structural_impls.rs @@ -236,7 +236,7 @@ impl fmt::Debug for ty::PredicateKind<'tcx> { ty::PredicateKind::RegionOutlives(ref pair) => pair.fmt(f), ty::PredicateKind::TypeOutlives(ref pair) => pair.fmt(f), ty::PredicateKind::Projection(ref pair) => pair.fmt(f), - ty::PredicateKind::WellFormed(ty) => write!(f, "WellFormed({:?})", ty), + ty::PredicateKind::WellFormed(data) => write!(f, "WellFormed({:?})", data), ty::PredicateKind::ObjectSafe(trait_def_id) => { write!(f, "ObjectSafe({:?})", trait_def_id) } @@ -247,7 +247,6 @@ impl fmt::Debug for ty::PredicateKind<'tcx> { write!(f, "ConstEvaluatable({:?}, {:?})", def_id, substs) } ty::PredicateKind::ConstEquate(c1, c2) => write!(f, "ConstEquate({:?}, {:?})", c1, c2), - ty::PredicateKind::WellFormedConst(c) => write!(f, "WellFormedConst({:?})", c), } } } @@ -508,9 +507,6 @@ impl<'a, 'tcx> Lift<'tcx> for ty::PredicateKind<'a> { ty::PredicateKind::ConstEquate(c1, c2) => { tcx.lift(&(c1, c2)).map(|(c1, c2)| ty::PredicateKind::ConstEquate(c1, c2)) } - ty::PredicateKind::WellFormedConst(c) => { - tcx.lift(&c).map(ty::PredicateKind::WellFormedConst) - } } } } diff --git a/src/librustc_mir/borrow_check/type_check/mod.rs b/src/librustc_mir/borrow_check/type_check/mod.rs index fdc3b291ba4..377a0b6f25c 100644 --- a/src/librustc_mir/borrow_check/type_check/mod.rs +++ b/src/librustc_mir/borrow_check/type_check/mod.rs @@ -1016,7 +1016,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> { } self.prove_predicate( - ty::PredicateKind::WellFormed(inferred_ty).to_predicate(self.tcx()), + ty::PredicateKind::WellFormed(inferred_ty.into()).to_predicate(self.tcx()), Locations::All(span), ConstraintCategory::TypeAnnotation, ); @@ -1268,7 +1268,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> { obligations.obligations.push(traits::Obligation::new( ObligationCause::dummy(), param_env, - ty::PredicateKind::WellFormed(revealed_ty).to_predicate(infcx.tcx), + ty::PredicateKind::WellFormed(revealed_ty.into()).to_predicate(infcx.tcx), )); obligations.add( infcx @@ -1612,7 +1612,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> { self.check_call_dest(body, term, &sig, destination, term_location); self.prove_predicates( - sig.inputs_and_output.iter().map(|ty| ty::PredicateKind::WellFormed(ty)), + sig.inputs_and_output.iter().map(|ty| ty::PredicateKind::WellFormed(ty.into())), term_location.to_locations(), ConstraintCategory::Boring, ); diff --git a/src/librustc_mir/transform/qualify_min_const_fn.rs b/src/librustc_mir/transform/qualify_min_const_fn.rs index 22959c6a3df..5615aa84eec 100644 --- a/src/librustc_mir/transform/qualify_min_const_fn.rs +++ b/src/librustc_mir/transform/qualify_min_const_fn.rs @@ -29,8 +29,7 @@ pub fn is_min_const_fn(tcx: TyCtxt<'tcx>, def_id: DefId, body: &'a Body<'tcx>) - | ty::PredicateKind::WellFormed(_) | ty::PredicateKind::Projection(_) | ty::PredicateKind::ConstEvaluatable(..) - | ty::PredicateKind::ConstEquate(..) - | ty::PredicateKind::WellFormedConst(..) => continue, + | ty::PredicateKind::ConstEquate(..) => continue, ty::PredicateKind::ObjectSafe(_) => { bug!("object safe predicate on function: {:#?}", predicate) } diff --git a/src/librustc_trait_selection/opaque_types.rs b/src/librustc_trait_selection/opaque_types.rs index 8bbcfb1ade5..f78a6207a3a 100644 --- a/src/librustc_trait_selection/opaque_types.rs +++ b/src/librustc_trait_selection/opaque_types.rs @@ -1277,8 +1277,7 @@ crate fn required_region_bounds( | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::RegionOutlives(..) | ty::PredicateKind::ConstEvaluatable(..) - | ty::PredicateKind::ConstEquate(..) - | ty::PredicateKind::WellFormedConst(..) => None, + | ty::PredicateKind::ConstEquate(..) => None, ty::PredicateKind::TypeOutlives(predicate) => { // Search for a bound of the form `erased_self_ty // : 'a`, but be wary of something like `for<'a> diff --git a/src/librustc_trait_selection/traits/error_reporting/mod.rs b/src/librustc_trait_selection/traits/error_reporting/mod.rs index 1134cafbae4..41811bf44b1 100644 --- a/src/librustc_trait_selection/traits/error_reporting/mod.rs +++ b/src/librustc_trait_selection/traits/error_reporting/mod.rs @@ -19,6 +19,7 @@ use rustc_hir::Node; use rustc_middle::mir::interpret::ErrorHandled; use rustc_middle::ty::error::ExpectedFound; use rustc_middle::ty::fold::TypeFolder; +use rustc_middle::ty::subst::GenericArgKind; use rustc_middle::ty::{ self, fast_reject, AdtKind, SubtypePredicate, ToPolyTraitRef, ToPredicate, Ty, TyCtxt, TypeFoldable, WithConstness, @@ -610,15 +611,6 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { } } - ty::PredicateKind::WellFormedConst(ct) => { - // Const WF predicates cannot themselves make - // errors. They can only block due to - // ambiguity; otherwise, they always - // degenerate into other obligations - // (which may fail). - span_bug!(span, "const WF predicate not satisfied for {:?}", ct); - } - ty::PredicateKind::ConstEvaluatable(..) => { // Errors for `ConstEvaluatable` predicates show up as // `SelectionError::ConstEvalFailure`, @@ -1540,22 +1532,24 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> { err } - ty::PredicateKind::WellFormed(ty) => { + ty::PredicateKind::WellFormed(arg) => { // Same hacky approach as above to avoid deluging user // with error messages. - if ty.references_error() || self.tcx.sess.has_errors() { + if arg.references_error() || self.tcx.sess.has_errors() { return; } - self.need_type_info_err(body_id, span, ty, ErrorCode::E0282) - } - ty::PredicateKind::WellFormedConst(ct) => { - // Same hacky approach as above to avoid deluging user - // with error messages. - if ct.references_error() || self.tcx.sess.has_errors() { - return; + match arg.unpack() { + GenericArgKind::Lifetime(lt) => { + span_bug!(span, "unexpected well formed predicate: {:?}", lt) + } + GenericArgKind::Type(ty) => { + self.need_type_info_err(body_id, span, ty, ErrorCode::E0282) + } + GenericArgKind::Const(ct) => { + self.need_type_info_err_const(body_id, span, ct, ErrorCode::E0282) + } } - self.need_type_info_err_const(body_id, span, ct, ErrorCode::E0282) } ty::PredicateKind::Subtype(ref data) => { diff --git a/src/librustc_trait_selection/traits/fulfill.rs b/src/librustc_trait_selection/traits/fulfill.rs index 8ab81246e7d..51c62dbb88c 100644 --- a/src/librustc_trait_selection/traits/fulfill.rs +++ b/src/librustc_trait_selection/traits/fulfill.rs @@ -459,38 +459,23 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> { } } - &ty::PredicateKind::WellFormed(ty) => { + &ty::PredicateKind::WellFormed(arg) => { match wf::obligations( self.selcx.infcx(), obligation.param_env, obligation.cause.body_id, - ty, + arg, obligation.cause.span, ) { None => { pending_obligation.stalled_on = - vec![TyOrConstInferVar::maybe_from_ty(ty).unwrap()]; + vec![TyOrConstInferVar::maybe_from_generic_arg(arg).unwrap()]; ProcessResult::Unchanged } Some(os) => ProcessResult::Changed(mk_pending(os)), } } - ty::PredicateKind::WellFormedConst(constant) => match wf::const_obligations( - self.selcx.infcx(), - obligation.param_env, - obligation.cause.body_id, - constant, - obligation.cause.span, - ) { - Some(predicates) => ProcessResult::Changed(mk_pending(predicates)), - None => { - pending_obligation.stalled_on = - vec![TyOrConstInferVar::maybe_from_const(constant).unwrap()]; - ProcessResult::Unchanged - } - }, - &ty::PredicateKind::Subtype(subtype) => { match self.selcx.infcx().subtype_predicate( &obligation.cause, diff --git a/src/librustc_trait_selection/traits/object_safety.rs b/src/librustc_trait_selection/traits/object_safety.rs index ee7aa6b165d..5befc797a51 100644 --- a/src/librustc_trait_selection/traits/object_safety.rs +++ b/src/librustc_trait_selection/traits/object_safety.rs @@ -283,8 +283,7 @@ fn predicates_reference_self( | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::Subtype(..) | ty::PredicateKind::ConstEvaluatable(..) - | ty::PredicateKind::ConstEquate(..) - | ty::PredicateKind::WellFormedConst(..) => None, + | ty::PredicateKind::ConstEquate(..) => None, } }) .collect() @@ -319,8 +318,7 @@ fn generics_require_sized_self(tcx: TyCtxt<'_>, def_id: DefId) -> bool { | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::TypeOutlives(..) | ty::PredicateKind::ConstEvaluatable(..) - | ty::PredicateKind::ConstEquate(..) - | ty::PredicateKind::WellFormedConst(..) => false, + | ty::PredicateKind::ConstEquate(..) => false, } }) } diff --git a/src/librustc_trait_selection/traits/select.rs b/src/librustc_trait_selection/traits/select.rs index 9dd0592c45f..517433b90ee 100644 --- a/src/librustc_trait_selection/traits/select.rs +++ b/src/librustc_trait_selection/traits/select.rs @@ -436,25 +436,11 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { } } - &ty::PredicateKind::WellFormed(ty) => match wf::obligations( + &ty::PredicateKind::WellFormed(arg) => match wf::obligations( self.infcx, obligation.param_env, obligation.cause.body_id, - ty, - obligation.cause.span, - ) { - Some(mut obligations) => { - self.add_depth(obligations.iter_mut(), obligation.recursion_depth); - self.evaluate_predicates_recursively(previous_stack, obligations.into_iter()) - } - None => Ok(EvaluatedToAmbig), - }, - - ty::PredicateKind::WellFormedConst(constant) => match wf::const_obligations( - self.infcx, - obligation.param_env, - obligation.cause.body_id, - constant, + arg, obligation.cause.span, ) { Some(mut obligations) => { diff --git a/src/librustc_trait_selection/traits/wf.rs b/src/librustc_trait_selection/traits/wf.rs index 458a6f5b88f..dde50a84952 100644 --- a/src/librustc_trait_selection/traits/wf.rs +++ b/src/librustc_trait_selection/traits/wf.rs @@ -9,9 +9,9 @@ use rustc_middle::ty::{self, ToPredicate, Ty, TyCtxt, TypeFoldable, WithConstnes use rustc_span::Span; use std::rc::Rc; -/// Returns the set of obligations needed to make `ty` well-formed. -/// If `ty` contains unresolved inference variables, this may include -/// further WF obligations. However, if `ty` IS an unresolved +/// Returns the set of obligations needed to make `arg` well-formed. +/// If `arg` contains unresolved inference variables, this may include +/// further WF obligations. However, if `arg` IS an unresolved /// inference variable, returns `None`, because we are not able to /// make any progress at all. This is to prevent "livelock" where we /// say "$0 is WF if $0 is WF". @@ -19,59 +19,51 @@ pub fn obligations<'a, 'tcx>( infcx: &InferCtxt<'a, 'tcx>, param_env: ty::ParamEnv<'tcx>, body_id: hir::HirId, - ty: Ty<'tcx>, + arg: GenericArg<'tcx>, span: Span, ) -> Option>> { // Handle the "livelock" case (see comment above) by bailing out if necessary. - let ty = match ty.kind { - ty::Infer(ty::TyVar(_)) => { - let resolved_ty = infcx.shallow_resolve(ty); - if resolved_ty == ty { - // No progress, bail out to prevent "livelock". - return None; - } + let arg = match arg.unpack() { + GenericArgKind::Type(ty) => { + match ty.kind { + ty::Infer(ty::TyVar(_)) => { + let resolved_ty = infcx.shallow_resolve(ty); + if resolved_ty == ty { + // No progress, bail out to prevent "livelock". + return None; + } - resolved_ty + resolved_ty + } + _ => ty, + } + .into() } - _ => ty, + GenericArgKind::Const(ct) => { + match ct.val { + ty::ConstKind::Infer(infer) => { + let resolved = infcx.shallow_resolve(infer); + if resolved == infer { + // No progress. + return None; + } + + infcx.tcx.mk_const(ty::Const { val: ty::ConstKind::Infer(resolved), ty: ct.ty }) + } + _ => ct, + } + .into() + } + // There is nothing we have to do for lifetimes. + GenericArgKind::Lifetime(..) => return Some(Vec::new()), }; let mut wf = WfPredicates { infcx, param_env, body_id, span, out: vec![], item: None }; - wf.compute(ty.into()); - debug!("wf::obligations({:?}, body_id={:?}) = {:?}", ty, body_id, wf.out); + wf.compute(arg); + debug!("wf::obligations({:?}, body_id={:?}) = {:?}", arg, body_id, wf.out); let result = wf.normalize(); - debug!("wf::obligations({:?}, body_id={:?}) ~~> {:?}", ty, body_id, result); - Some(result) -} - -/// Returns the set of obligations needed to make the `constant` well-formed. -pub fn const_obligations<'a, 'tcx>( - infcx: &InferCtxt<'a, 'tcx>, - param_env: ty::ParamEnv<'tcx>, - body_id: hir::HirId, - constant: &'tcx ty::Const<'tcx>, - span: Span, -) -> Option>> { - let constant = match constant.val { - ty::ConstKind::Infer(infer) => { - let resolved = infcx.shallow_resolve(infer); - if resolved == infer { - // No progress. - return None; - } - - infcx.tcx.mk_const(ty::Const { val: ty::ConstKind::Infer(resolved), ..*constant }) - } - _ => constant, - }; - - let mut wf = WfPredicates { infcx, param_env, body_id, span, out: vec![], item: None }; - wf.compute(constant.into()); - debug!("wf::const obligations({:?}, body_id={:?}) = {:?}", constant, body_id, wf.out); - - let result = wf.normalize(); - debug!("wf::const obligations({:?}, body_id={:?}) ~~> {:?}", constant, body_id, result); + debug!("wf::obligations({:?}, body_id={:?}) ~~> {:?}", arg, body_id, result); Some(result) } @@ -115,8 +107,8 @@ pub fn predicate_obligations<'a, 'tcx>( wf.compute_projection(t.projection_ty); wf.compute(t.ty.into()); } - &ty::PredicateKind::WellFormed(t) => { - wf.compute(t.into()); + &ty::PredicateKind::WellFormed(arg) => { + wf.compute(arg); } ty::PredicateKind::ObjectSafe(_) => {} ty::PredicateKind::ClosureKind(..) => {} @@ -128,17 +120,14 @@ pub fn predicate_obligations<'a, 'tcx>( let obligations = wf.nominal_obligations(def_id, substs); wf.out.extend(obligations); - for subst in substs.iter() { - wf.compute(subst); + for arg in substs.iter() { + wf.compute(arg); } } &ty::PredicateKind::ConstEquate(c1, c2) => { wf.compute(c1.into()); wf.compute(c2.into()); } - &ty::PredicateKind::WellFormedConst(constant) => { - wf.compute(constant.into()); - } } wf.normalize() @@ -306,15 +295,22 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> { } let tcx = self.tcx(); - self.out.extend(trait_ref.substs.types().filter(|ty| !ty.has_escaping_bound_vars()).map( - |ty| { - traits::Obligation::new( - cause.clone(), - param_env, - ty::PredicateKind::WellFormed(ty).to_predicate(tcx), - ) - }, - )); + self.out.extend( + trait_ref + .substs + .iter() + .filter(|arg| { + matches!(arg.unpack(), GenericArgKind::Type(..) | GenericArgKind::Const(..)) + }) + .filter(|arg| !arg.has_escaping_bound_vars()) + .map(|arg| { + traits::Obligation::new( + cause.clone(), + param_env, + ty::PredicateKind::WellFormed(arg).to_predicate(tcx), + ) + }), + ); } /// Pushes the obligations required for `trait_ref::Item` to be WF @@ -390,7 +386,7 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> { self.out.push(traits::Obligation::new( cause, self.param_env, - ty::PredicateKind::WellFormedConst(resolved_constant) + ty::PredicateKind::WellFormed(resolved_constant.into()) .to_predicate(self.tcx()), )); } @@ -594,7 +590,7 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> { self.out.push(traits::Obligation::new( cause, param_env, - ty::PredicateKind::WellFormed(ty).to_predicate(self.tcx()), + ty::PredicateKind::WellFormed(ty.into()).to_predicate(self.tcx()), )); } else { // Yes, resolved, proceed with the result. diff --git a/src/librustc_traits/chalk/lowering.rs b/src/librustc_traits/chalk/lowering.rs index b624598322a..9530b07e47c 100644 --- a/src/librustc_traits/chalk/lowering.rs +++ b/src/librustc_traits/chalk/lowering.rs @@ -36,7 +36,7 @@ use rustc_middle::traits::{ ChalkRustInterner as RustInterner, }; use rustc_middle::ty::fold::TypeFolder; -use rustc_middle::ty::subst::{GenericArg, SubstsRef}; +use rustc_middle::ty::subst::{GenericArg, GenericArgKind, SubstsRef}; use rustc_middle::ty::{ self, Binder, BoundRegion, Region, RegionKind, Ty, TyCtxt, TyKind, TypeFoldable, TypeVisitor, }; @@ -126,8 +126,7 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::InEnvironment { + | ty::PredicateKind::ConstEquate(..) => { bug!("unexpected predicate {}", predicate) } } @@ -166,24 +165,31 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::GoalData>> for ty::Predi chalk_ir::GoalData::All(chalk_ir::Goals::new(interner)) } ty::PredicateKind::Projection(predicate) => predicate.lower_into(interner), - ty::PredicateKind::WellFormed(ty) => match ty.kind { - // These types are always WF. - ty::Str | ty::Placeholder(..) | ty::Error | ty::Never => { + ty::PredicateKind::WellFormed(arg) => match arg.unpack() { + GenericArgKind::Type(ty) => match ty.kind { + // These types are always WF. + ty::Str | ty::Placeholder(..) | ty::Error | ty::Never => { + chalk_ir::GoalData::All(chalk_ir::Goals::new(interner)) + } + + // FIXME(chalk): Well-formed only if ref lifetime outlives type + ty::Ref(..) => chalk_ir::GoalData::All(chalk_ir::Goals::new(interner)), + + ty::Param(..) => panic!("No Params expected."), + + // FIXME(chalk) -- ultimately I think this is what we + // want to do, and we just have rules for how to prove + // `WellFormed` for everything above, instead of + // inlining a bit the rules of the proof here. + _ => chalk_ir::GoalData::DomainGoal(chalk_ir::DomainGoal::WellFormed( + chalk_ir::WellFormed::Ty(ty.lower_into(interner)), + )), + }, + // FIXME(chalk): handle well formed consts + GenericArgKind::Const(..) => { chalk_ir::GoalData::All(chalk_ir::Goals::new(interner)) } - - // FIXME(chalk): Well-formed only if ref lifetime outlives type - ty::Ref(..) => chalk_ir::GoalData::All(chalk_ir::Goals::new(interner)), - - ty::Param(..) => panic!("No Params expected."), - - // FIXME(chalk) -- ultimately I think this is what we - // want to do, and we just have rules for how to prove - // `WellFormed` for everything above, instead of - // inlining a bit the rules of the proof here. - _ => chalk_ir::GoalData::DomainGoal(chalk_ir::DomainGoal::WellFormed( - chalk_ir::WellFormed::Ty(ty.lower_into(interner)), - )), + GenericArgKind::Lifetime(lt) => bug!("unexpect well formed predicate: {:?}", lt), }, // FIXME(chalk): other predicates @@ -194,8 +200,7 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::GoalData>> for ty::Predi | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::Subtype(..) | ty::PredicateKind::ConstEvaluatable(..) - | ty::PredicateKind::ConstEquate(..) - | ty::PredicateKind::WellFormedConst(..) => { + | ty::PredicateKind::ConstEquate(..) => { chalk_ir::GoalData::All(chalk_ir::Goals::new(interner)) } } @@ -462,8 +467,7 @@ impl<'tcx> LowerInto<'tcx, Option bug!("unexpected predicate {}", &self), + | ty::PredicateKind::ConstEquate(..) => bug!("unexpected predicate {}", &self), } } } diff --git a/src/librustc_traits/implied_outlives_bounds.rs b/src/librustc_traits/implied_outlives_bounds.rs index 073dfe4d592..651596d0379 100644 --- a/src/librustc_traits/implied_outlives_bounds.rs +++ b/src/librustc_traits/implied_outlives_bounds.rs @@ -47,14 +47,14 @@ fn compute_implied_outlives_bounds<'tcx>( // process it next. Currently (at least) these resulting // predicates are always guaranteed to be a subset of the original // type, so we need not fear non-termination. - let mut wf_types = vec![ty]; + let mut wf_args = vec![ty.into()]; let mut implied_bounds = vec![]; let mut fulfill_cx = FulfillmentContext::new(); - while let Some(ty) = wf_types.pop() { - // Compute the obligations for `ty` to be well-formed. If `ty` is + while let Some(arg) = wf_args.pop() { + // Compute the obligations for `arg` to be well-formed. If `arg` is // an unresolved inference variable, just substituted an empty set // -- because the return type here is going to be things we *add* // to the environment, it's always ok for this set to be smaller @@ -62,7 +62,7 @@ fn compute_implied_outlives_bounds<'tcx>( // unresolved inference variables here anyway, but there might be // during typeck under some circumstances.) let obligations = - wf::obligations(infcx, param_env, hir::CRATE_HIR_ID, ty, DUMMY_SP).unwrap_or(vec![]); + wf::obligations(infcx, param_env, hir::CRATE_HIR_ID, arg, DUMMY_SP).unwrap_or(vec![]); // N.B., all of these predicates *ought* to be easily proven // true. In fact, their correctness is (mostly) implied by @@ -101,11 +101,10 @@ fn compute_implied_outlives_bounds<'tcx>( | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::ObjectSafe(..) | ty::PredicateKind::ConstEvaluatable(..) - | ty::PredicateKind::ConstEquate(..) - | ty::PredicateKind::WellFormedConst(..) => vec![], + | ty::PredicateKind::ConstEquate(..) => vec![], - ty::PredicateKind::WellFormed(subty) => { - wf_types.push(subty); + &ty::PredicateKind::WellFormed(arg) => { + wf_args.push(arg); vec![] } diff --git a/src/librustc_traits/normalize_erasing_regions.rs b/src/librustc_traits/normalize_erasing_regions.rs index 6a8d81085c5..fcb75142269 100644 --- a/src/librustc_traits/normalize_erasing_regions.rs +++ b/src/librustc_traits/normalize_erasing_regions.rs @@ -49,7 +49,6 @@ fn not_outlives_predicate(p: &ty::Predicate<'_>) -> bool { | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::Subtype(..) | ty::PredicateKind::ConstEvaluatable(..) - | ty::PredicateKind::ConstEquate(..) - | ty::PredicateKind::WellFormedConst(..) => true, + | ty::PredicateKind::ConstEquate(..) => true, } } diff --git a/src/librustc_traits/type_op.rs b/src/librustc_traits/type_op.rs index 22077b49c3b..374ef3fc9c7 100644 --- a/src/librustc_traits/type_op.rs +++ b/src/librustc_traits/type_op.rs @@ -140,7 +140,7 @@ impl AscribeUserTypeCx<'me, 'tcx> { self.relate(self_ty, Variance::Invariant, impl_self_ty)?; self.prove_predicate( - ty::PredicateKind::WellFormed(impl_self_ty).to_predicate(self.tcx()), + ty::PredicateKind::WellFormed(impl_self_ty.into()).to_predicate(self.tcx()), ); } @@ -155,7 +155,7 @@ impl AscribeUserTypeCx<'me, 'tcx> { // them? This would only be relevant if some input // type were ill-formed but did not appear in `ty`, // which...could happen with normalization... - self.prove_predicate(ty::PredicateKind::WellFormed(ty).to_predicate(self.tcx())); + self.prove_predicate(ty::PredicateKind::WellFormed(ty.into()).to_predicate(self.tcx())); Ok(()) } } diff --git a/src/librustc_typeck/check/callee.rs b/src/librustc_typeck/check/callee.rs index f4e46a04931..aa316105f7f 100644 --- a/src/librustc_typeck/check/callee.rs +++ b/src/librustc_typeck/check/callee.rs @@ -94,7 +94,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { }; // we must check that return type of called functions is WF: - self.register_wf_obligation(output, call_expr.span, traits::MiscObligation); + self.register_wf_obligation(output.into(), call_expr.span, traits::MiscObligation); output } diff --git a/src/librustc_typeck/check/method/confirm.rs b/src/librustc_typeck/check/method/confirm.rs index 48d27387476..007794ce1b7 100644 --- a/src/librustc_typeck/check/method/confirm.rs +++ b/src/librustc_typeck/check/method/confirm.rs @@ -413,7 +413,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> { // the function type must also be well-formed (this is not // implied by the substs being well-formed because of inherent // impls and late-bound regions - see issue #28609). - self.register_wf_obligation(fty, self.span, traits::MiscObligation); + self.register_wf_obligation(fty.into(), self.span, traits::MiscObligation); } /////////////////////////////////////////////////////////////////////////// diff --git a/src/librustc_typeck/check/method/mod.rs b/src/librustc_typeck/check/method/mod.rs index aae02ea0273..ac3fa15417e 100644 --- a/src/librustc_typeck/check/method/mod.rs +++ b/src/librustc_typeck/check/method/mod.rs @@ -401,7 +401,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { obligations.push(traits::Obligation::new( cause, self.param_env, - ty::PredicateKind::WellFormed(method_ty).to_predicate(tcx), + ty::PredicateKind::WellFormed(method_ty.into()).to_predicate(tcx), )); let callee = MethodCallee { def_id, substs: trait_ref.substs, sig: fn_sig }; diff --git a/src/librustc_typeck/check/method/probe.rs b/src/librustc_typeck/check/method/probe.rs index c17b3d78125..91562d576ea 100644 --- a/src/librustc_typeck/check/method/probe.rs +++ b/src/librustc_typeck/check/method/probe.rs @@ -814,8 +814,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> { | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::TypeOutlives(..) | ty::PredicateKind::ConstEvaluatable(..) - | ty::PredicateKind::ConstEquate(..) - | ty::PredicateKind::WellFormedConst(..) => None, + | ty::PredicateKind::ConstEquate(..) => None, }); self.elaborate_bounds(bounds, |this, poly_trait_ref, item| { diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs index 374ba1c7314..275581318f7 100644 --- a/src/librustc_typeck/check/mod.rs +++ b/src/librustc_typeck/check/mod.rs @@ -121,9 +121,8 @@ use rustc_middle::ty::adjustment::{ }; use rustc_middle::ty::fold::{TypeFoldable, TypeFolder}; use rustc_middle::ty::query::Providers; -use rustc_middle::ty::subst::{ - GenericArgKind, InternalSubsts, Subst, SubstsRef, UserSelfTy, UserSubsts, -}; +use rustc_middle::ty::subst::{self, InternalSubsts, Subst, SubstsRef}; +use rustc_middle::ty::subst::{GenericArgKind, UserSelfTy, UserSubsts}; use rustc_middle::ty::util::{Discr, IntTypeExt, Representability}; use rustc_middle::ty::{ self, AdtKind, CanonicalUserType, Const, GenericParamDefKind, RegionKind, ToPolyTraitRef, @@ -3333,7 +3332,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { pub fn to_ty(&self, ast_t: &hir::Ty<'_>) -> Ty<'tcx> { let t = AstConv::ast_ty_to_ty(self, ast_t); - self.register_wf_obligation(t, ast_t.span, traits::MiscObligation); + self.register_wf_obligation(t.into(), ast_t.span, traits::MiscObligation); t } @@ -3353,8 +3352,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { pub fn to_const(&self, ast_c: &hir::AnonConst) -> &'tcx ty::Const<'tcx> { let const_def_id = self.tcx.hir().local_def_id(ast_c.hir_id); let c = ty::Const::from_anon_const(self.tcx, const_def_id); - self.register_wf_const_obligation( - c, + self.register_wf_obligation( + c.into(), self.tcx.hir().span(ast_c.hir_id), ObligationCauseCode::MiscObligation, ); @@ -3394,7 +3393,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { /// outlive the region `r`. pub fn register_wf_obligation( &self, - ty: Ty<'tcx>, + arg: subst::GenericArg<'tcx>, span: Span, code: traits::ObligationCauseCode<'tcx>, ) { @@ -3403,45 +3402,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { self.register_predicate(traits::Obligation::new( cause, self.param_env, - ty::PredicateKind::WellFormed(ty).to_predicate(self.tcx), - )); - } - - /// Registers an obligation for checking later, during regionck, that the type `ty` must - /// outlive the region `r`. - pub fn register_wf_const_obligation( - &self, - ct: &'tcx ty::Const<'tcx>, - span: Span, - code: traits::ObligationCauseCode<'tcx>, - ) { - // WF obligations never themselves fail, so no real need to give a detailed cause: - let cause = traits::ObligationCause::new(span, self.body_id, code); - self.register_predicate(traits::Obligation::new( - cause, - self.param_env, - ty::PredicateKind::WellFormedConst(ct).to_predicate(self.tcx), + ty::PredicateKind::WellFormed(arg).to_predicate(self.tcx), )); } /// Registers obligations that all `substs` are well-formed. pub fn add_wf_bounds(&self, substs: SubstsRef<'tcx>, expr: &hir::Expr<'_>) { - for subst in substs { - match subst.unpack() { - GenericArgKind::Lifetime(..) => { - // Nothing to do for lifetimes. - } - GenericArgKind::Type(ty) => { - if !ty.references_error() { - self.register_wf_obligation(ty, expr.span, traits::MiscObligation); - } - } - GenericArgKind::Const(ct) => { - if !ct.references_error() { - self.register_wf_const_obligation(ct, expr.span, traits::MiscObligation); - } - } - } + for arg in substs.iter().filter(|arg| { + matches!(arg.unpack(), GenericArgKind::Type(..) | GenericArgKind::Const(..)) + }) { + self.register_wf_obligation(arg, expr.span, traits::MiscObligation); } } @@ -3872,7 +3842,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { ty::PredicateKind::RegionOutlives(..) => None, ty::PredicateKind::TypeOutlives(..) => None, ty::PredicateKind::WellFormed(..) => None, - ty::PredicateKind::WellFormedConst(..) => None, ty::PredicateKind::ObjectSafe(..) => None, ty::PredicateKind::ConstEvaluatable(..) => None, ty::PredicateKind::ConstEquate(..) => None, @@ -3914,8 +3883,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // All the input types from the fn signature must outlive the call // so as to validate implied bounds. - for (fn_input_ty, arg_expr) in fn_inputs.iter().zip(args.iter()) { - self.register_wf_obligation(fn_input_ty, arg_expr.span, traits::MiscObligation); + for (&fn_input_ty, arg_expr) in fn_inputs.iter().zip(args.iter()) { + self.register_wf_obligation(fn_input_ty.into(), arg_expr.span, traits::MiscObligation); } let expected_arg_count = fn_inputs.len(); diff --git a/src/librustc_typeck/check/wfcheck.rs b/src/librustc_typeck/check/wfcheck.rs index e154184f182..7d9bf975c69 100644 --- a/src/librustc_typeck/check/wfcheck.rs +++ b/src/librustc_typeck/check/wfcheck.rs @@ -292,7 +292,7 @@ fn check_associated_item( ty::AssocKind::Const => { let ty = fcx.tcx.type_of(item.def_id); let ty = fcx.normalize_associated_types_in(span, &ty); - fcx.register_wf_obligation(ty, span, code.clone()); + fcx.register_wf_obligation(ty.into(), span, code.clone()); } ty::AssocKind::Fn => { let sig = fcx.tcx.fn_sig(item.def_id); @@ -313,7 +313,7 @@ fn check_associated_item( if item.defaultness.has_value() { let ty = fcx.tcx.type_of(item.def_id); let ty = fcx.normalize_associated_types_in(span, &ty); - fcx.register_wf_obligation(ty, span, code.clone()); + fcx.register_wf_obligation(ty.into(), span, code.clone()); } } ty::AssocKind::OpaqueTy => { @@ -406,7 +406,7 @@ fn check_type_defn<'tcx, F>( // All field types must be well-formed. for field in &variant.fields { fcx.register_wf_obligation( - field.ty, + field.ty.into(), field.span, ObligationCauseCode::MiscObligation, ) @@ -601,7 +601,7 @@ fn check_item_type(tcx: TyCtxt<'_>, item_id: hir::HirId, ty_span: Span, allow_fo } } - fcx.register_wf_obligation(item_ty, ty_span, ObligationCauseCode::MiscObligation); + fcx.register_wf_obligation(item_ty.into(), ty_span, ObligationCauseCode::MiscObligation); if forbid_unsized { fcx.register_bound( item_ty, @@ -650,7 +650,7 @@ fn check_impl<'tcx>( let self_ty = fcx.tcx.type_of(item_def_id); let self_ty = fcx.normalize_associated_types_in(item.span, &self_ty); fcx.register_wf_obligation( - self_ty, + self_ty.into(), ast_self_ty.span, ObligationCauseCode::MiscObligation, ); @@ -698,7 +698,7 @@ fn check_where_clauses<'tcx, 'fcx>( // be sure if it will error or not as user might always specify the other. if !ty.needs_subst() { fcx.register_wf_obligation( - ty, + ty.into(), fcx.tcx.def_span(param.def_id), ObligationCauseCode::MiscObligation, ); @@ -841,13 +841,13 @@ fn check_fn_or_method<'fcx, 'tcx>( let sig = fcx.normalize_associated_types_in(span, &sig); let sig = fcx.tcx.liberate_late_bound_regions(def_id, &sig); - for (input_ty, span) in sig.inputs().iter().zip(hir_sig.decl.inputs.iter().map(|t| t.span)) { - fcx.register_wf_obligation(&input_ty, span, ObligationCauseCode::MiscObligation); + for (&input_ty, span) in sig.inputs().iter().zip(hir_sig.decl.inputs.iter().map(|t| t.span)) { + fcx.register_wf_obligation(input_ty.into(), span, ObligationCauseCode::MiscObligation); } implied_bounds.extend(sig.inputs()); fcx.register_wf_obligation( - sig.output(), + sig.output().into(), hir_sig.decl.output.span(), ObligationCauseCode::ReturnType, ); diff --git a/src/librustc_typeck/impl_wf_check/min_specialization.rs b/src/librustc_typeck/impl_wf_check/min_specialization.rs index b2e8716b038..e4bffedd620 100644 --- a/src/librustc_typeck/impl_wf_check/min_specialization.rs +++ b/src/librustc_typeck/impl_wf_check/min_specialization.rs @@ -332,12 +332,12 @@ fn check_predicates<'tcx>( }); // Include the well-formed predicates of the type parameters of the impl. - for ty in tcx.impl_trait_ref(impl1_def_id).unwrap().substs.types() { + for arg in tcx.impl_trait_ref(impl1_def_id).unwrap().substs { if let Some(obligations) = wf::obligations( infcx, tcx.param_env(impl1_def_id), tcx.hir().as_local_hir_id(impl1_def_id), - ty, + arg, span, ) { impl2_predicates @@ -405,7 +405,6 @@ fn trait_predicate_kind<'tcx>( | ty::PredicateKind::ObjectSafe(_) | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::ConstEvaluatable(..) - | ty::PredicateKind::ConstEquate(..) - | ty::PredicateKind::WellFormedConst(..) => None, + | ty::PredicateKind::ConstEquate(..) => None, } } diff --git a/src/librustc_typeck/outlives/explicit.rs b/src/librustc_typeck/outlives/explicit.rs index cf8be687f60..5740cc224cc 100644 --- a/src/librustc_typeck/outlives/explicit.rs +++ b/src/librustc_typeck/outlives/explicit.rs @@ -59,8 +59,7 @@ impl<'tcx> ExplicitPredicatesMap<'tcx> { | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::Subtype(..) | ty::PredicateKind::ConstEvaluatable(..) - | ty::PredicateKind::ConstEquate(..) - | ty::PredicateKind::WellFormedConst(..) => (), + | ty::PredicateKind::ConstEquate(..) => (), } } diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs index 5c2d6c6453d..371df7444b0 100644 --- a/src/librustdoc/clean/mod.rs +++ b/src/librustdoc/clean/mod.rs @@ -491,8 +491,7 @@ impl<'a> Clean> for ty::Predicate<'a> { | ty::PredicateKind::ObjectSafe(..) | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::ConstEvaluatable(..) - | ty::PredicateKind::ConstEquate(..) - | ty::PredicateKind::WellFormedConst(..) => panic!("not user writable"), + | ty::PredicateKind::ConstEquate(..) => panic!("not user writable"), } } }