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Diffstat (limited to 'crates/hir-ty/src/next_solver/infer/resolve.rs')
| -rw-r--r-- | crates/hir-ty/src/next_solver/infer/resolve.rs | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/crates/hir-ty/src/next_solver/infer/resolve.rs b/crates/hir-ty/src/next_solver/infer/resolve.rs new file mode 100644 index 0000000000..84338ade6e --- /dev/null +++ b/crates/hir-ty/src/next_solver/infer/resolve.rs @@ -0,0 +1,62 @@ +//! Things for resolving vars in the infer context of the next-trait-solver. + +use rustc_type_ir::{ + ConstKind, FallibleTypeFolder, InferConst, InferTy, RegionKind, TyKind, TypeFoldable, + TypeFolder, TypeSuperFoldable, TypeVisitableExt, data_structures::DelayedMap, + inherent::IntoKind, +}; + +use crate::next_solver::{Const, DbInterner, Region, Ty}; + +use super::{FixupError, FixupResult, InferCtxt}; + +/////////////////////////////////////////////////////////////////////////// +// OPPORTUNISTIC VAR RESOLVER + +/// The opportunistic resolver can be used at any time. It simply replaces +/// type/const variables that have been unified with the things they have +/// been unified with (similar to `shallow_resolve`, but deep). This is +/// useful for printing messages etc but also required at various +/// points for correctness. +pub struct OpportunisticVarResolver<'a, 'db> { + infcx: &'a InferCtxt<'db>, + /// We're able to use a cache here as the folder does + /// not have any mutable state. + cache: DelayedMap<Ty<'db>, Ty<'db>>, +} + +impl<'a, 'db> OpportunisticVarResolver<'a, 'db> { + #[inline] + pub fn new(infcx: &'a InferCtxt<'db>) -> Self { + OpportunisticVarResolver { infcx, cache: Default::default() } + } +} + +impl<'a, 'db> TypeFolder<DbInterner<'db>> for OpportunisticVarResolver<'a, 'db> { + fn cx(&self) -> DbInterner<'db> { + self.infcx.interner + } + + #[inline] + fn fold_ty(&mut self, t: Ty<'db>) -> Ty<'db> { + if !t.has_non_region_infer() { + t // micro-optimize -- if there is nothing in this type that this fold affects... + } else if let Some(ty) = self.cache.get(&t) { + *ty + } else { + let shallow = self.infcx.shallow_resolve(t); + let res = shallow.super_fold_with(self); + assert!(self.cache.insert(t, res)); + res + } + } + + fn fold_const(&mut self, ct: Const<'db>) -> Const<'db> { + if !ct.has_non_region_infer() { + ct // micro-optimize -- if there is nothing in this const that this fold affects... + } else { + let ct = self.infcx.shallow_resolve_const(ct); + ct.super_fold_with(self) + } + } +} |