Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir-ty/src/next_solver/region.rs')
| -rw-r--r-- | crates/hir-ty/src/next_solver/region.rs | 335 |
1 files changed, 335 insertions, 0 deletions
diff --git a/crates/hir-ty/src/next_solver/region.rs b/crates/hir-ty/src/next_solver/region.rs new file mode 100644 index 0000000000..d6214d9915 --- /dev/null +++ b/crates/hir-ty/src/next_solver/region.rs @@ -0,0 +1,335 @@ +//! Things related to regions. + +use hir_def::LifetimeParamId; +use intern::{Interned, Symbol}; +use rustc_type_ir::{ + BoundVar, Flags, INNERMOST, RegionVid, TypeFlags, TypeFoldable, TypeVisitable, VisitorResult, + inherent::{IntoKind, PlaceholderLike, SliceLike}, + relate::Relate, +}; + +use crate::next_solver::{GenericArg, OutlivesPredicate}; + +use super::{ + ErrorGuaranteed, SolverDefId, interned_vec_db, + interner::{BoundVarKind, DbInterner, Placeholder}, +}; + +type RegionKind<'db> = rustc_type_ir::RegionKind<DbInterner<'db>>; + +#[salsa::interned(constructor = new_, debug)] +pub struct Region<'db> { + #[returns(ref)] + kind_: RegionKind<'db>, +} + +impl<'db> Region<'db> { + pub fn new(interner: DbInterner<'db>, kind: RegionKind<'db>) -> Self { + Region::new_(interner.db(), kind) + } + + pub fn inner(&self) -> &RegionKind<'db> { + salsa::with_attached_database(|db| { + let inner = self.kind_(db); + // SAFETY: The caller already has access to a `Region<'db>`, so borrowchecking will + // make sure that our returned value is valid for the lifetime `'db`. + unsafe { std::mem::transmute::<&RegionKind<'_>, &RegionKind<'db>>(inner) } + }) + .unwrap() + } + + pub fn new_early_param( + interner: DbInterner<'db>, + early_bound_region: EarlyParamRegion, + ) -> Self { + Region::new(interner, RegionKind::ReEarlyParam(early_bound_region)) + } + + pub fn new_placeholder(interner: DbInterner<'db>, placeholder: PlaceholderRegion) -> Self { + Region::new(interner, RegionKind::RePlaceholder(placeholder)) + } + + pub fn new_var(interner: DbInterner<'db>, v: RegionVid) -> Region<'db> { + Region::new(interner, RegionKind::ReVar(v)) + } + + pub fn is_placeholder(&self) -> bool { + matches!(self.inner(), RegionKind::RePlaceholder(..)) + } + + pub fn is_static(&self) -> bool { + matches!(self.inner(), RegionKind::ReStatic) + } + + pub fn error(interner: DbInterner<'db>) -> Self { + Region::new(interner, RegionKind::ReError(ErrorGuaranteed)) + } + + pub fn type_flags(&self) -> TypeFlags { + let mut flags = TypeFlags::empty(); + + match &self.inner() { + RegionKind::ReVar(..) => { + flags |= TypeFlags::HAS_FREE_REGIONS; + flags |= TypeFlags::HAS_FREE_LOCAL_REGIONS; + flags |= TypeFlags::HAS_RE_INFER; + } + RegionKind::RePlaceholder(..) => { + flags |= TypeFlags::HAS_FREE_REGIONS; + flags |= TypeFlags::HAS_FREE_LOCAL_REGIONS; + flags |= TypeFlags::HAS_RE_PLACEHOLDER; + } + RegionKind::ReEarlyParam(..) => { + flags |= TypeFlags::HAS_FREE_REGIONS; + flags |= TypeFlags::HAS_FREE_LOCAL_REGIONS; + flags |= TypeFlags::HAS_RE_PARAM; + } + RegionKind::ReLateParam(..) => { + flags |= TypeFlags::HAS_FREE_REGIONS; + flags |= TypeFlags::HAS_FREE_LOCAL_REGIONS; + } + RegionKind::ReStatic => { + flags |= TypeFlags::HAS_FREE_REGIONS; + } + RegionKind::ReBound(..) => { + flags |= TypeFlags::HAS_RE_BOUND; + } + RegionKind::ReErased => { + flags |= TypeFlags::HAS_RE_ERASED; + } + RegionKind::ReError(..) => { + flags |= TypeFlags::HAS_FREE_REGIONS; + flags |= TypeFlags::HAS_ERROR; + } + } + + flags + } +} + +pub type PlaceholderRegion = Placeholder<BoundRegion>; + +#[derive(Copy, Clone, PartialEq, Eq, Hash)] +pub struct EarlyParamRegion { + // FIXME: See `ParamTy`. + pub id: LifetimeParamId, + pub index: u32, +} + +#[derive(Copy, Clone, PartialEq, Eq, Hash)] +/// The parameter representation of late-bound function parameters, "some region +/// at least as big as the scope `fr.scope`". +/// +/// Similar to a placeholder region as we create `LateParam` regions when entering a binder +/// except they are always in the root universe and instead of using a boundvar to distinguish +/// between others we use the `DefId` of the parameter. For this reason the `bound_region` field +/// should basically always be `BoundRegionKind::Named` as otherwise there is no way of telling +/// different parameters apart. +pub struct LateParamRegion { + pub scope: SolverDefId, + pub bound_region: BoundRegionKind, +} + +impl std::fmt::Debug for LateParamRegion { + fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { + write!(f, "ReLateParam({:?}, {:?})", self.scope, self.bound_region) + } +} + +#[derive(Copy, Clone, PartialEq, Eq, Hash)] +pub enum BoundRegionKind { + /// An anonymous region parameter for a given fn (&T) + Anon, + + /// Named region parameters for functions (a in &'a T) + /// + /// The `DefId` is needed to distinguish free regions in + /// the event of shadowing. + Named(SolverDefId), + + /// Anonymous region for the implicit env pointer parameter + /// to a closure + ClosureEnv, +} + +impl std::fmt::Debug for BoundRegionKind { + fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { + match *self { + BoundRegionKind::Anon => write!(f, "BrAnon"), + BoundRegionKind::Named(did) => { + write!(f, "BrNamed({did:?})") + } + BoundRegionKind::ClosureEnv => write!(f, "BrEnv"), + } + } +} + +#[derive(Copy, Clone, PartialEq, Eq, Hash)] +pub struct BoundRegion { + pub var: BoundVar, + pub kind: BoundRegionKind, +} + +impl rustc_type_ir::inherent::ParamLike for EarlyParamRegion { + fn index(self) -> u32 { + self.index + } +} + +impl std::fmt::Debug for EarlyParamRegion { + fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { + write!(f, "#{}", self.index) + // write!(f, "{}/#{}", self.name, self.index) + } +} + +impl<'db> rustc_type_ir::inherent::BoundVarLike<DbInterner<'db>> for BoundRegion { + fn var(self) -> BoundVar { + self.var + } + + fn assert_eq(self, var: BoundVarKind) { + assert_eq!(self.kind, var.expect_region()) + } +} + +impl core::fmt::Debug for BoundRegion { + fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { + match &self.kind { + BoundRegionKind::Anon => write!(f, "{:?}", self.var), + BoundRegionKind::ClosureEnv => write!(f, "{:?}.Env", self.var), + BoundRegionKind::Named(def) => { + write!(f, "{:?}.Named({:?})", self.var, def) + } + } + } +} + +impl BoundRegionKind { + pub fn is_named(&self) -> bool { + matches!(self, BoundRegionKind::Named(_)) + } + + pub fn get_name(&self) -> Option<Symbol> { + None + } + + pub fn get_id(&self) -> Option<SolverDefId> { + match self { + BoundRegionKind::Named(id) => Some(*id), + _ => None, + } + } +} + +impl<'db> IntoKind for Region<'db> { + type Kind = RegionKind<'db>; + + fn kind(self) -> Self::Kind { + *self.inner() + } +} + +impl<'db> TypeVisitable<DbInterner<'db>> for Region<'db> { + fn visit_with<V: rustc_type_ir::TypeVisitor<DbInterner<'db>>>( + &self, + visitor: &mut V, + ) -> V::Result { + visitor.visit_region(*self) + } +} + +impl<'db> TypeFoldable<DbInterner<'db>> for Region<'db> { + fn try_fold_with<F: rustc_type_ir::FallibleTypeFolder<DbInterner<'db>>>( + self, + folder: &mut F, + ) -> Result<Self, F::Error> { + folder.try_fold_region(self) + } + fn fold_with<F: rustc_type_ir::TypeFolder<DbInterner<'db>>>(self, folder: &mut F) -> Self { + folder.fold_region(self) + } +} + +impl<'db> Relate<DbInterner<'db>> for Region<'db> { + fn relate<R: rustc_type_ir::relate::TypeRelation<DbInterner<'db>>>( + relation: &mut R, + a: Self, + b: Self, + ) -> rustc_type_ir::relate::RelateResult<DbInterner<'db>, Self> { + relation.regions(a, b) + } +} + +impl<'db> Flags for Region<'db> { + fn flags(&self) -> rustc_type_ir::TypeFlags { + self.type_flags() + } + + fn outer_exclusive_binder(&self) -> rustc_type_ir::DebruijnIndex { + match &self.inner() { + RegionKind::ReBound(debruijn, _) => debruijn.shifted_in(1), + _ => INNERMOST, + } + } +} + +impl<'db> rustc_type_ir::inherent::Region<DbInterner<'db>> for Region<'db> { + fn new_bound( + interner: DbInterner<'db>, + debruijn: rustc_type_ir::DebruijnIndex, + var: BoundRegion, + ) -> Self { + Region::new(interner, RegionKind::ReBound(debruijn, var)) + } + + fn new_anon_bound( + interner: DbInterner<'db>, + debruijn: rustc_type_ir::DebruijnIndex, + var: rustc_type_ir::BoundVar, + ) -> Self { + Region::new( + interner, + RegionKind::ReBound(debruijn, BoundRegion { var, kind: BoundRegionKind::Anon }), + ) + } + + fn new_static(interner: DbInterner<'db>) -> Self { + Region::new(interner, RegionKind::ReStatic) + } + + fn new_placeholder( + interner: DbInterner<'db>, + var: <DbInterner<'db> as rustc_type_ir::Interner>::PlaceholderRegion, + ) -> Self { + Region::new(interner, RegionKind::RePlaceholder(var)) + } +} + +impl<'db> PlaceholderLike<DbInterner<'db>> for PlaceholderRegion { + type Bound = BoundRegion; + + fn universe(self) -> rustc_type_ir::UniverseIndex { + self.universe + } + + fn var(self) -> rustc_type_ir::BoundVar { + self.bound.var + } + + fn with_updated_universe(self, ui: rustc_type_ir::UniverseIndex) -> Self { + Placeholder { universe: ui, bound: self.bound } + } + + fn new(ui: rustc_type_ir::UniverseIndex, bound: Self::Bound) -> Self { + Placeholder { universe: ui, bound } + } + + fn new_anon(ui: rustc_type_ir::UniverseIndex, var: rustc_type_ir::BoundVar) -> Self { + Placeholder { universe: ui, bound: BoundRegion { var, kind: BoundRegionKind::Anon } } + } +} + +type GenericArgOutlivesPredicate<'db> = OutlivesPredicate<'db, GenericArg<'db>>; + +interned_vec_db!(RegionAssumptions, GenericArgOutlivesPredicate); |