1 files changed, 423 insertions, 0 deletions

diff --git a/crates/hir_ty/src/interner.rs b/crates/hir_ty/src/interner.rs
new file mode 100644
index 000000000..a1656115d
--- /dev/null
+++ b/crates/hir_ty/src/interner.rs
@@ -0,0 +1,423 @@
+//! Implementation of the Chalk `Interner` trait, which allows customizing the
+//! representation of the various objects Chalk deals with (types, goals etc.).
+
+use crate::{chalk_db, tls, GenericArg};
+use base_db::salsa::InternId;
+use chalk_ir::{Goal, GoalData};
+use hir_def::{
+    intern::{impl_internable, InternStorage, Internable, Interned},
+    TypeAliasId,
+};
+use smallvec::SmallVec;
+use std::{fmt, sync::Arc};
+
+#[derive(Debug, Copy, Clone, Hash, PartialOrd, Ord, PartialEq, Eq)]
+pub struct Interner;
+
+#[derive(PartialEq, Eq, Hash, Debug)]
+pub struct InternedWrapper<T>(T);
+
+impl<T> std::ops::Deref for InternedWrapper<T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl_internable!(
+    InternedWrapper<Vec<chalk_ir::VariableKind<Interner>>>,
+    InternedWrapper<SmallVec<[GenericArg; 2]>>,
+    InternedWrapper<chalk_ir::TyData<Interner>>,
+    InternedWrapper<chalk_ir::LifetimeData<Interner>>,
+    InternedWrapper<chalk_ir::ConstData<Interner>>,
+    InternedWrapper<Vec<chalk_ir::CanonicalVarKind<Interner>>>,
+    InternedWrapper<Vec<chalk_ir::ProgramClause<Interner>>>,
+    InternedWrapper<Vec<chalk_ir::QuantifiedWhereClause<Interner>>>,
+    InternedWrapper<Vec<chalk_ir::Variance>>,
+);
+
+impl chalk_ir::interner::Interner for Interner {
+    type InternedType = Interned<InternedWrapper<chalk_ir::TyData<Interner>>>;
+    type InternedLifetime = Interned<InternedWrapper<chalk_ir::LifetimeData<Self>>>;
+    type InternedConst = Interned<InternedWrapper<chalk_ir::ConstData<Self>>>;
+    type InternedConcreteConst = ();
+    type InternedGenericArg = chalk_ir::GenericArgData<Self>;
+    type InternedGoal = Arc<GoalData<Self>>;
+    type InternedGoals = Vec<Goal<Self>>;
+    type InternedSubstitution = Interned<InternedWrapper<SmallVec<[GenericArg; 2]>>>;
+    type InternedProgramClause = chalk_ir::ProgramClauseData<Self>;
+    type InternedProgramClauses = Interned<InternedWrapper<Vec<chalk_ir::ProgramClause<Self>>>>;
+    type InternedQuantifiedWhereClauses =
+        Interned<InternedWrapper<Vec<chalk_ir::QuantifiedWhereClause<Self>>>>;
+    type InternedVariableKinds = Interned<InternedWrapper<Vec<chalk_ir::VariableKind<Interner>>>>;
+    type InternedCanonicalVarKinds =
+        Interned<InternedWrapper<Vec<chalk_ir::CanonicalVarKind<Self>>>>;
+    type InternedConstraints = Vec<chalk_ir::InEnvironment<chalk_ir::Constraint<Self>>>;
+    type InternedVariances = Interned<InternedWrapper<Vec<chalk_ir::Variance>>>;
+    type DefId = InternId;
+    type InternedAdtId = hir_def::AdtId;
+    type Identifier = TypeAliasId;
+    type FnAbi = ();
+
+    fn debug_adt_id(
+        type_kind_id: chalk_db::AdtId,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_struct_id(type_kind_id, fmt)))
+    }
+
+    fn debug_trait_id(
+        type_kind_id: chalk_db::TraitId,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_trait_id(type_kind_id, fmt)))
+    }
+
+    fn debug_assoc_type_id(
+        id: chalk_db::AssocTypeId,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_assoc_type_id(id, fmt)))
+    }
+
+    fn debug_alias(
+        alias: &chalk_ir::AliasTy<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_alias(alias, fmt)))
+    }
+
+    fn debug_projection_ty(
+        proj: &chalk_ir::ProjectionTy<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_projection_ty(proj, fmt)))
+    }
+
+    fn debug_opaque_ty(
+        opaque_ty: &chalk_ir::OpaqueTy<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_opaque_ty(opaque_ty, fmt)))
+    }
+
+    fn debug_opaque_ty_id(
+        opaque_ty_id: chalk_ir::OpaqueTyId<Self>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_opaque_ty_id(opaque_ty_id, fmt)))
+    }
+
+    fn debug_ty(ty: &chalk_ir::Ty<Interner>, fmt: &mut fmt::Formatter<'_>) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_ty(ty, fmt)))
+    }
+
+    fn debug_lifetime(
+        lifetime: &chalk_ir::Lifetime<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_lifetime(lifetime, fmt)))
+    }
+
+    fn debug_generic_arg(
+        parameter: &GenericArg,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_generic_arg(parameter, fmt)))
+    }
+
+    fn debug_goal(goal: &Goal<Interner>, fmt: &mut fmt::Formatter<'_>) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_goal(goal, fmt)))
+    }
+
+    fn debug_goals(
+        goals: &chalk_ir::Goals<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_goals(goals, fmt)))
+    }
+
+    fn debug_program_clause_implication(
+        pci: &chalk_ir::ProgramClauseImplication<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_program_clause_implication(pci, fmt)))
+    }
+
+    fn debug_substitution(
+        substitution: &chalk_ir::Substitution<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_substitution(substitution, fmt)))
+    }
+
+    fn debug_separator_trait_ref(
+        separator_trait_ref: &chalk_ir::SeparatorTraitRef<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| {
+            Some(prog?.debug_separator_trait_ref(separator_trait_ref, fmt))
+        })
+    }
+
+    fn debug_fn_def_id(
+        fn_def_id: chalk_ir::FnDefId<Self>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_fn_def_id(fn_def_id, fmt)))
+    }
+    fn debug_const(
+        constant: &chalk_ir::Const<Self>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_const(constant, fmt)))
+    }
+    fn debug_variable_kinds(
+        variable_kinds: &chalk_ir::VariableKinds<Self>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_variable_kinds(variable_kinds, fmt)))
+    }
+    fn debug_variable_kinds_with_angles(
+        variable_kinds: &chalk_ir::VariableKinds<Self>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| {
+            Some(prog?.debug_variable_kinds_with_angles(variable_kinds, fmt))
+        })
+    }
+    fn debug_canonical_var_kinds(
+        canonical_var_kinds: &chalk_ir::CanonicalVarKinds<Self>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| {
+            Some(prog?.debug_canonical_var_kinds(canonical_var_kinds, fmt))
+        })
+    }
+    fn debug_program_clause(
+        clause: &chalk_ir::ProgramClause<Self>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_program_clause(clause, fmt)))
+    }
+    fn debug_program_clauses(
+        clauses: &chalk_ir::ProgramClauses<Self>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_program_clauses(clauses, fmt)))
+    }
+    fn debug_quantified_where_clauses(
+        clauses: &chalk_ir::QuantifiedWhereClauses<Self>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_quantified_where_clauses(clauses, fmt)))
+    }
+
+    fn intern_ty(&self, kind: chalk_ir::TyKind<Self>) -> Self::InternedType {
+        let flags = kind.compute_flags(self);
+        Interned::new(InternedWrapper(chalk_ir::TyData { kind, flags }))
+    }
+
+    fn ty_data<'a>(&self, ty: &'a Self::InternedType) -> &'a chalk_ir::TyData<Self> {
+        &ty.0
+    }
+
+    fn intern_lifetime(&self, lifetime: chalk_ir::LifetimeData<Self>) -> Self::InternedLifetime {
+        Interned::new(InternedWrapper(lifetime))
+    }
+
+    fn lifetime_data<'a>(
+        &self,
+        lifetime: &'a Self::InternedLifetime,
+    ) -> &'a chalk_ir::LifetimeData<Self> {
+        &lifetime.0
+    }
+
+    fn intern_const(&self, constant: chalk_ir::ConstData<Self>) -> Self::InternedConst {
+        Interned::new(InternedWrapper(constant))
+    }
+
+    fn const_data<'a>(&self, constant: &'a Self::InternedConst) -> &'a chalk_ir::ConstData<Self> {
+        &constant.0
+    }
+
+    fn const_eq(
+        &self,
+        _ty: &Self::InternedType,
+        _c1: &Self::InternedConcreteConst,
+        _c2: &Self::InternedConcreteConst,
+    ) -> bool {
+        true
+    }
+
+    fn intern_generic_arg(
+        &self,
+        parameter: chalk_ir::GenericArgData<Self>,
+    ) -> Self::InternedGenericArg {
+        parameter
+    }
+
+    fn generic_arg_data<'a>(
+        &self,
+        parameter: &'a Self::InternedGenericArg,
+    ) -> &'a chalk_ir::GenericArgData<Self> {
+        parameter
+    }
+
+    fn intern_goal(&self, goal: GoalData<Self>) -> Self::InternedGoal {
+        Arc::new(goal)
+    }
+
+    fn intern_goals<E>(
+        &self,
+        data: impl IntoIterator<Item = Result<Goal<Self>, E>>,
+    ) -> Result<Self::InternedGoals, E> {
+        data.into_iter().collect()
+    }
+
+    fn goal_data<'a>(&self, goal: &'a Self::InternedGoal) -> &'a GoalData<Self> {
+        goal
+    }
+
+    fn goals_data<'a>(&self, goals: &'a Self::InternedGoals) -> &'a [Goal<Interner>] {
+        goals
+    }
+
+    fn intern_substitution<E>(
+        &self,
+        data: impl IntoIterator<Item = Result<GenericArg, E>>,
+    ) -> Result<Self::InternedSubstitution, E> {
+        Ok(Interned::new(InternedWrapper(data.into_iter().collect::<Result<_, _>>()?)))
+    }
+
+    fn substitution_data<'a>(
+        &self,
+        substitution: &'a Self::InternedSubstitution,
+    ) -> &'a [GenericArg] {
+        &substitution.as_ref().0
+    }
+
+    fn intern_program_clause(
+        &self,
+        data: chalk_ir::ProgramClauseData<Self>,
+    ) -> Self::InternedProgramClause {
+        data
+    }
+
+    fn program_clause_data<'a>(
+        &self,
+        clause: &'a Self::InternedProgramClause,
+    ) -> &'a chalk_ir::ProgramClauseData<Self> {
+        clause
+    }
+
+    fn intern_program_clauses<E>(
+        &self,
+        data: impl IntoIterator<Item = Result<chalk_ir::ProgramClause<Self>, E>>,
+    ) -> Result<Self::InternedProgramClauses, E> {
+        Ok(Interned::new(InternedWrapper(data.into_iter().collect::<Result<_, _>>()?)))
+    }
+
+    fn program_clauses_data<'a>(
+        &self,
+        clauses: &'a Self::InternedProgramClauses,
+    ) -> &'a [chalk_ir::ProgramClause<Self>] {
+        &clauses
+    }
+
+    fn intern_quantified_where_clauses<E>(
+        &self,
+        data: impl IntoIterator<Item = Result<chalk_ir::QuantifiedWhereClause<Self>, E>>,
+    ) -> Result<Self::InternedQuantifiedWhereClauses, E> {
+        Ok(Interned::new(InternedWrapper(data.into_iter().collect::<Result<_, _>>()?)))
+    }
+
+    fn quantified_where_clauses_data<'a>(
+        &self,
+        clauses: &'a Self::InternedQuantifiedWhereClauses,
+    ) -> &'a [chalk_ir::QuantifiedWhereClause<Self>] {
+        clauses
+    }
+
+    fn intern_generic_arg_kinds<E>(
+        &self,
+        data: impl IntoIterator<Item = Result<chalk_ir::VariableKind<Self>, E>>,
+    ) -> Result<Self::InternedVariableKinds, E> {
+        Ok(Interned::new(InternedWrapper(data.into_iter().collect::<Result<_, _>>()?)))
+    }
+
+    fn variable_kinds_data<'a>(
+        &self,
+        parameter_kinds: &'a Self::InternedVariableKinds,
+    ) -> &'a [chalk_ir::VariableKind<Self>] {
+        &parameter_kinds.as_ref().0
+    }
+
+    fn intern_canonical_var_kinds<E>(
+        &self,
+        data: impl IntoIterator<Item = Result<chalk_ir::CanonicalVarKind<Self>, E>>,
+    ) -> Result<Self::InternedCanonicalVarKinds, E> {
+        Ok(Interned::new(InternedWrapper(data.into_iter().collect::<Result<_, _>>()?)))
+    }
+
+    fn canonical_var_kinds_data<'a>(
+        &self,
+        canonical_var_kinds: &'a Self::InternedCanonicalVarKinds,
+    ) -> &'a [chalk_ir::CanonicalVarKind<Self>] {
+        &canonical_var_kinds
+    }
+
+    fn intern_constraints<E>(
+        &self,
+        data: impl IntoIterator<Item = Result<chalk_ir::InEnvironment<chalk_ir::Constraint<Self>>, E>>,
+    ) -> Result<Self::InternedConstraints, E> {
+        data.into_iter().collect()
+    }
+
+    fn constraints_data<'a>(
+        &self,
+        constraints: &'a Self::InternedConstraints,
+    ) -> &'a [chalk_ir::InEnvironment<chalk_ir::Constraint<Self>>] {
+        constraints
+    }
+    fn debug_closure_id(
+        _fn_def_id: chalk_ir::ClosureId<Self>,
+        _fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        None
+    }
+    fn debug_constraints(
+        _clauses: &chalk_ir::Constraints<Self>,
+        _fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        None
+    }
+
+    fn intern_variances<E>(
+        &self,
+        data: impl IntoIterator<Item = Result<chalk_ir::Variance, E>>,
+    ) -> Result<Self::InternedVariances, E> {
+        Ok(Interned::new(InternedWrapper(data.into_iter().collect::<Result<_, _>>()?)))
+    }
+
+    fn variances_data<'a>(
+        &self,
+        variances: &'a Self::InternedVariances,
+    ) -> &'a [chalk_ir::Variance] {
+        &variances
+    }
+}
+
+impl chalk_ir::interner::HasInterner for Interner {
+    type Interner = Self;
+}
+
+#[macro_export]
+macro_rules! has_interner {
+    ($t:ty) => {
+        impl HasInterner for $t {
+            type Interner = crate::Interner;
+        }
+    };
+}