diff options
Diffstat (limited to 'compiler/rustc_ty_utils/src/instance.rs')
| -rw-r--r-- | compiler/rustc_ty_utils/src/instance.rs | 123 |
1 files changed, 9 insertions, 114 deletions
diff --git a/compiler/rustc_ty_utils/src/instance.rs b/compiler/rustc_ty_utils/src/instance.rs index bd1d568cd..05738b6c4 100644 --- a/compiler/rustc_ty_utils/src/instance.rs +++ b/compiler/rustc_ty_utils/src/instance.rs @@ -3,115 +3,11 @@ use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_infer::infer::TyCtxtInferExt; use rustc_middle::traits::CodegenObligationError; use rustc_middle::ty::subst::SubstsRef; -use rustc_middle::ty::{ - self, Binder, Instance, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor, -}; +use rustc_middle::ty::{self, Instance, TyCtxt, TypeVisitable}; use rustc_span::{sym, DUMMY_SP}; use rustc_trait_selection::traits; use traits::{translate_substs, Reveal}; -use rustc_data_structures::sso::SsoHashSet; -use std::collections::btree_map::Entry; -use std::collections::BTreeMap; -use std::ops::ControlFlow; - -use tracing::debug; - -// FIXME(#86795): `BoundVarsCollector` here should **NOT** be used -// outside of `resolve_associated_item`. It's just to address #64494, -// #83765, and #85848 which are creating bound types/regions that lose -// their `Binder` *unintentionally*. -// It's ideal to remove `BoundVarsCollector` and just use -// `ty::Binder::*` methods but we use this stopgap until we figure out -// the "real" fix. -struct BoundVarsCollector<'tcx> { - binder_index: ty::DebruijnIndex, - vars: BTreeMap<u32, ty::BoundVariableKind>, - // We may encounter the same variable at different levels of binding, so - // this can't just be `Ty` - visited: SsoHashSet<(ty::DebruijnIndex, Ty<'tcx>)>, -} - -impl<'tcx> BoundVarsCollector<'tcx> { - fn new() -> Self { - BoundVarsCollector { - binder_index: ty::INNERMOST, - vars: BTreeMap::new(), - visited: SsoHashSet::default(), - } - } - - fn into_vars(self, tcx: TyCtxt<'tcx>) -> &'tcx ty::List<ty::BoundVariableKind> { - let max = self.vars.iter().map(|(k, _)| *k).max().unwrap_or(0); - for i in 0..max { - if let None = self.vars.get(&i) { - panic!("Unknown variable: {:?}", i); - } - } - - tcx.mk_bound_variable_kinds(self.vars.into_iter().map(|(_, v)| v)) - } -} - -impl<'tcx> TypeVisitor<'tcx> for BoundVarsCollector<'tcx> { - type BreakTy = (); - - fn visit_binder<T: TypeVisitable<'tcx>>( - &mut self, - t: &Binder<'tcx, T>, - ) -> ControlFlow<Self::BreakTy> { - self.binder_index.shift_in(1); - let result = t.super_visit_with(self); - self.binder_index.shift_out(1); - result - } - - fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> { - if t.outer_exclusive_binder() < self.binder_index - || !self.visited.insert((self.binder_index, t)) - { - return ControlFlow::CONTINUE; - } - match *t.kind() { - ty::Bound(debruijn, bound_ty) if debruijn == self.binder_index => { - match self.vars.entry(bound_ty.var.as_u32()) { - Entry::Vacant(entry) => { - entry.insert(ty::BoundVariableKind::Ty(bound_ty.kind)); - } - Entry::Occupied(entry) => match entry.get() { - ty::BoundVariableKind::Ty(_) => {} - _ => bug!("Conflicting bound vars"), - }, - } - } - - _ => (), - }; - - t.super_visit_with(self) - } - - fn visit_region(&mut self, r: ty::Region<'tcx>) -> ControlFlow<Self::BreakTy> { - match *r { - ty::ReLateBound(index, br) if index == self.binder_index => { - match self.vars.entry(br.var.as_u32()) { - Entry::Vacant(entry) => { - entry.insert(ty::BoundVariableKind::Region(br.kind)); - } - Entry::Occupied(entry) => match entry.get() { - ty::BoundVariableKind::Region(_) => {} - _ => bug!("Conflicting bound vars"), - }, - } - } - - _ => (), - }; - - r.super_visit_with(self) - } -} - fn resolve_instance<'tcx>( tcx: TyCtxt<'tcx>, key: ty::ParamEnvAnd<'tcx, (DefId, SubstsRef<'tcx>)>, @@ -203,19 +99,14 @@ fn resolve_associated_item<'tcx>( let trait_ref = ty::TraitRef::from_method(tcx, trait_id, rcvr_substs); - // See FIXME on `BoundVarsCollector`. - let mut bound_vars_collector = BoundVarsCollector::new(); - trait_ref.visit_with(&mut bound_vars_collector); - let trait_binder = ty::Binder::bind_with_vars(trait_ref, bound_vars_collector.into_vars(tcx)); - let vtbl = match tcx.codegen_fulfill_obligation((param_env, trait_binder)) { + let vtbl = match tcx.codegen_select_candidate((param_env, ty::Binder::dummy(trait_ref))) { Ok(vtbl) => vtbl, Err(CodegenObligationError::Ambiguity) => { let reported = tcx.sess.delay_span_bug( tcx.def_span(trait_item_id), &format!( - "encountered ambiguity selecting `{:?}` during codegen, presuming due to \ + "encountered ambiguity selecting `{trait_ref:?}` during codegen, presuming due to \ overflow or prior type error", - trait_binder ), ); return Err(reported); @@ -372,7 +263,10 @@ fn resolve_associated_item<'tcx>( let is_copy = self_ty.is_copy_modulo_regions(tcx.at(DUMMY_SP), param_env); match self_ty.kind() { _ if is_copy => (), - ty::Closure(..) | ty::Tuple(..) => {} + ty::Generator(..) + | ty::GeneratorWitness(..) + | ty::Closure(..) + | ty::Tuple(..) => {} _ => return Ok(None), }; @@ -397,7 +291,8 @@ fn resolve_associated_item<'tcx>( | traits::ImplSource::DiscriminantKind(..) | traits::ImplSource::Pointee(..) | traits::ImplSource::TraitUpcasting(_) - | traits::ImplSource::ConstDestruct(_) => None, + | traits::ImplSource::ConstDestruct(_) + | traits::ImplSource::Tuple => None, }) } |