diff options
Diffstat (limited to 'compiler/rustc_middle/src/ty/util.rs')
| -rw-r--r-- | compiler/rustc_middle/src/ty/util.rs | 93 |
1 files changed, 32 insertions, 61 deletions
diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs index 318bd0c7ec0..88d57498542 100644 --- a/compiler/rustc_middle/src/ty/util.rs +++ b/compiler/rustc_middle/src/ty/util.rs @@ -5,9 +5,10 @@ use std::{fmt, iter}; use rustc_abi::{ExternAbi, Float, Integer, IntegerType, Size}; use rustc_apfloat::Float as _; use rustc_data_structures::fx::{FxHashMap, FxHashSet}; -use rustc_data_structures::stable_hasher::{Hash128, HashStable, StableHasher}; +use rustc_data_structures::stable_hasher::{HashStable, StableHasher}; use rustc_data_structures::stack::ensure_sufficient_stack; use rustc_errors::ErrorGuaranteed; +use rustc_hashes::Hash128; use rustc_hir as hir; use rustc_hir::def::{CtorOf, DefKind, Res}; use rustc_hir::def_id::{CrateNum, DefId, LocalDefId}; @@ -759,10 +760,11 @@ impl<'tcx> TyCtxt<'tcx> { assert_eq!(re, self.lifetimes.re_erased); let var = ty::BoundVar::from_usize(vars.len()); vars.push(ty::BoundVariableKind::Region(ty::BoundRegionKind::Anon)); - ty::Region::new_bound(self, debruijn, ty::BoundRegion { - var, - kind: ty::BoundRegionKind::Anon, - }) + ty::Region::new_bound( + self, + debruijn, + ty::BoundRegion { var, kind: ty::BoundRegionKind::Anon }, + ) }); ty::EarlyBinder::bind(ty::Binder::bind_with_vars( ty, @@ -777,7 +779,6 @@ impl<'tcx> TyCtxt<'tcx> { self, def_id: DefId, args: GenericArgsRef<'tcx>, - inspect_coroutine_fields: InspectCoroutineFields, ) -> Result<Ty<'tcx>, Ty<'tcx>> { let mut visitor = OpaqueTypeExpander { seen_opaque_tys: FxHashSet::default(), @@ -786,9 +787,7 @@ impl<'tcx> TyCtxt<'tcx> { found_recursion: false, found_any_recursion: false, check_recursion: true, - expand_coroutines: true, tcx: self, - inspect_coroutine_fields, }; let expanded_type = visitor.expand_opaque_ty(def_id, args).unwrap(); @@ -951,6 +950,29 @@ impl<'tcx> TyCtxt<'tcx> { ty } + + // Computes the variances for an alias (opaque or RPITIT) that represent + // its (un)captured regions. + pub fn opt_alias_variances( + self, + kind: impl Into<ty::AliasTermKind>, + def_id: DefId, + ) -> Option<&'tcx [ty::Variance]> { + match kind.into() { + ty::AliasTermKind::ProjectionTy => { + if self.is_impl_trait_in_trait(def_id) { + Some(self.variances_of(def_id)) + } else { + None + } + } + ty::AliasTermKind::OpaqueTy => Some(self.variances_of(def_id)), + ty::AliasTermKind::InherentTy + | ty::AliasTermKind::WeakTy + | ty::AliasTermKind::UnevaluatedConst + | ty::AliasTermKind::ProjectionConst => None, + } + } } struct OpaqueTypeExpander<'tcx> { @@ -965,19 +987,11 @@ struct OpaqueTypeExpander<'tcx> { primary_def_id: Option<DefId>, found_recursion: bool, found_any_recursion: bool, - expand_coroutines: bool, /// Whether or not to check for recursive opaque types. /// This is `true` when we're explicitly checking for opaque type /// recursion, and 'false' otherwise to avoid unnecessary work. check_recursion: bool, tcx: TyCtxt<'tcx>, - inspect_coroutine_fields: InspectCoroutineFields, -} - -#[derive(Copy, Clone, PartialEq, Eq, Debug)] -pub enum InspectCoroutineFields { - No, - Yes, } impl<'tcx> OpaqueTypeExpander<'tcx> { @@ -1009,41 +1023,6 @@ impl<'tcx> OpaqueTypeExpander<'tcx> { None } } - - fn expand_coroutine(&mut self, def_id: DefId, args: GenericArgsRef<'tcx>) -> Option<Ty<'tcx>> { - if self.found_any_recursion { - return None; - } - let args = args.fold_with(self); - if !self.check_recursion || self.seen_opaque_tys.insert(def_id) { - let expanded_ty = match self.expanded_cache.get(&(def_id, args)) { - Some(expanded_ty) => *expanded_ty, - None => { - if matches!(self.inspect_coroutine_fields, InspectCoroutineFields::Yes) { - for bty in self.tcx.bound_coroutine_hidden_types(def_id) { - let hidden_ty = self.tcx.instantiate_bound_regions_with_erased( - bty.instantiate(self.tcx, args), - ); - self.fold_ty(hidden_ty); - } - } - let expanded_ty = Ty::new_coroutine_witness(self.tcx, def_id, args); - self.expanded_cache.insert((def_id, args), expanded_ty); - expanded_ty - } - }; - if self.check_recursion { - self.seen_opaque_tys.remove(&def_id); - } - Some(expanded_ty) - } else { - // If another opaque type that we contain is recursive, then it - // will report the error, so we don't have to. - self.found_any_recursion = true; - self.found_recursion = def_id == *self.primary_def_id.as_ref().unwrap(); - None - } - } } impl<'tcx> TypeFolder<TyCtxt<'tcx>> for OpaqueTypeExpander<'tcx> { @@ -1052,19 +1031,13 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for OpaqueTypeExpander<'tcx> { } fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> { - let mut t = if let ty::Alias(ty::Opaque, ty::AliasTy { def_id, args, .. }) = *t.kind() { + if let ty::Alias(ty::Opaque, ty::AliasTy { def_id, args, .. }) = *t.kind() { self.expand_opaque_ty(def_id, args).unwrap_or(t) - } else if t.has_opaque_types() || t.has_coroutines() { + } else if t.has_opaque_types() { t.super_fold_with(self) } else { t - }; - if self.expand_coroutines { - if let ty::CoroutineWitness(def_id, args) = *t.kind() { - t = self.expand_coroutine(def_id, args).unwrap_or(t); - } } - t } fn fold_predicate(&mut self, p: ty::Predicate<'tcx>) -> ty::Predicate<'tcx> { @@ -1753,9 +1726,7 @@ pub fn reveal_opaque_types_in_bounds<'tcx>( found_recursion: false, found_any_recursion: false, check_recursion: false, - expand_coroutines: false, tcx, - inspect_coroutine_fields: InspectCoroutineFields::No, }; val.fold_with(&mut visitor) } |