1 files changed, 403 insertions, 0 deletions
diff --git a/compiler/rustc_middle/src/traits/chalk.rs b/compiler/rustc_middle/src/traits/chalk.rs
new file mode 100644
index 000000000..6d4af8bea
--- /dev/null
+++ b/compiler/rustc_middle/src/traits/chalk.rs
@@ -0,0 +1,403 @@
+//! Types required for Chalk-related queries
+//!
+//! The primary purpose of this file is defining an implementation for the
+//! `chalk_ir::interner::Interner` trait. The primary purpose of this trait, as
+//! its name suggest, is to provide an abstraction boundary for creating
+//! interned Chalk types.
+
+use rustc_middle::ty::{self, AdtDef, TyCtxt};
+
+use rustc_hir::def_id::DefId;
+use rustc_target::spec::abi::Abi;
+
+use std::cmp::Ordering;
+use std::fmt;
+use std::hash::{Hash, Hasher};
+
+#[derive(Copy, Clone)]
+pub struct RustInterner<'tcx> {
+    pub tcx: TyCtxt<'tcx>,
+}
+
+/// We don't ever actually need this. It's only required for derives.
+impl<'tcx> Hash for RustInterner<'tcx> {
+    fn hash<H: Hasher>(&self, _state: &mut H) {}
+}
+
+/// We don't ever actually need this. It's only required for derives.
+impl<'tcx> Ord for RustInterner<'tcx> {
+    fn cmp(&self, _other: &Self) -> Ordering {
+        Ordering::Equal
+    }
+}
+
+/// We don't ever actually need this. It's only required for derives.
+impl<'tcx> PartialOrd for RustInterner<'tcx> {
+    fn partial_cmp(&self, _other: &Self) -> Option<Ordering> {
+        None
+    }
+}
+
+/// We don't ever actually need this. It's only required for derives.
+impl<'tcx> PartialEq for RustInterner<'tcx> {
+    fn eq(&self, _other: &Self) -> bool {
+        false
+    }
+}
+
+/// We don't ever actually need this. It's only required for derives.
+impl<'tcx> Eq for RustInterner<'tcx> {}
+
+impl fmt::Debug for RustInterner<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "RustInterner")
+    }
+}
+
+// Right now, there is no interning at all. I was running into problems with
+// adding interning in `ty/context.rs` for Chalk types with
+// `parallel-compiler = true`. -jackh726
+impl<'tcx> chalk_ir::interner::Interner for RustInterner<'tcx> {
+    type InternedType = Box<chalk_ir::TyData<Self>>;
+    type InternedLifetime = Box<chalk_ir::LifetimeData<Self>>;
+    type InternedConst = Box<chalk_ir::ConstData<Self>>;
+    type InternedConcreteConst = ty::ValTree<'tcx>;
+    type InternedGenericArg = Box<chalk_ir::GenericArgData<Self>>;
+    type InternedGoal = Box<chalk_ir::GoalData<Self>>;
+    type InternedGoals = Vec<chalk_ir::Goal<Self>>;
+    type InternedSubstitution = Vec<chalk_ir::GenericArg<Self>>;
+    type InternedProgramClause = Box<chalk_ir::ProgramClauseData<Self>>;
+    type InternedProgramClauses = Vec<chalk_ir::ProgramClause<Self>>;
+    type InternedQuantifiedWhereClauses = Vec<chalk_ir::QuantifiedWhereClause<Self>>;
+    type InternedVariableKinds = Vec<chalk_ir::VariableKind<Self>>;
+    type InternedCanonicalVarKinds = Vec<chalk_ir::CanonicalVarKind<Self>>;
+    type InternedVariances = Vec<chalk_ir::Variance>;
+    type InternedConstraints = Vec<chalk_ir::InEnvironment<chalk_ir::Constraint<Self>>>;
+    type DefId = DefId;
+    type InternedAdtId = AdtDef<'tcx>;
+    type Identifier = ();
+    type FnAbi = Abi;
+
+    fn debug_program_clause_implication(
+        pci: &chalk_ir::ProgramClauseImplication<Self>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        let mut write = || {
+            write!(fmt, "{:?}", pci.consequence)?;
+
+            let conditions = pci.conditions.interned();
+            let constraints = pci.constraints.interned();
+
+            let conds = conditions.len();
+            let consts = constraints.len();
+            if conds == 0 && consts == 0 {
+                return Ok(());
+            }
+
+            write!(fmt, " :- ")?;
+
+            if conds != 0 {
+                for cond in &conditions[..conds - 1] {
+                    write!(fmt, "{:?}, ", cond)?;
+                }
+                write!(fmt, "{:?}", conditions[conds - 1])?;
+            }
+
+            if conds != 0 && consts != 0 {
+                write!(fmt, " ; ")?;
+            }
+
+            if consts != 0 {
+                for constraint in &constraints[..consts - 1] {
+                    write!(fmt, "{:?}, ", constraint)?;
+                }
+                write!(fmt, "{:?}", constraints[consts - 1])?;
+            }
+
+            Ok(())
+        };
+        Some(write())
+    }
+
+    fn debug_substitution(
+        substitution: &chalk_ir::Substitution<Self>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        Some(write!(fmt, "{:?}", substitution.interned()))
+    }
+
+    fn debug_separator_trait_ref(
+        separator_trait_ref: &chalk_ir::SeparatorTraitRef<'_, Self>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        let substitution = &separator_trait_ref.trait_ref.substitution;
+        let parameters = substitution.interned();
+        Some(write!(
+            fmt,
+            "{:?}{}{:?}{:?}",
+            parameters[0],
+            separator_trait_ref.separator,
+            separator_trait_ref.trait_ref.trait_id,
+            chalk_ir::debug::Angle(&parameters[1..])
+        ))
+    }
+
+    fn debug_quantified_where_clauses(
+        clauses: &chalk_ir::QuantifiedWhereClauses<Self>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        Some(write!(fmt, "{:?}", clauses.interned()))
+    }
+
+    fn debug_ty(ty: &chalk_ir::Ty<Self>, fmt: &mut fmt::Formatter<'_>) -> Option<fmt::Result> {
+        match &ty.interned().kind {
+            chalk_ir::TyKind::Ref(chalk_ir::Mutability::Not, lifetime, ty) => {
+                Some(write!(fmt, "(&{:?} {:?})", lifetime, ty))
+            }
+            chalk_ir::TyKind::Ref(chalk_ir::Mutability::Mut, lifetime, ty) => {
+                Some(write!(fmt, "(&{:?} mut {:?})", lifetime, ty))
+            }
+            chalk_ir::TyKind::Array(ty, len) => Some(write!(fmt, "[{:?}; {:?}]", ty, len)),
+            chalk_ir::TyKind::Slice(ty) => Some(write!(fmt, "[{:?}]", ty)),
+            chalk_ir::TyKind::Tuple(len, substs) => Some((|| {
+                write!(fmt, "(")?;
+                for (idx, substitution) in substs.interned().iter().enumerate() {
+                    if idx == *len && *len != 1 {
+                        // Don't add a trailing comma if the tuple has more than one element
+                        write!(fmt, "{:?}", substitution)?;
+                    } else {
+                        write!(fmt, "{:?},", substitution)?;
+                    }
+                }
+                write!(fmt, ")")
+            })()),
+            _ => None,
+        }
+    }
+
+    fn debug_alias(
+        alias_ty: &chalk_ir::AliasTy<Self>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        match alias_ty {
+            chalk_ir::AliasTy::Projection(projection_ty) => {
+                Self::debug_projection_ty(projection_ty, fmt)
+            }
+            chalk_ir::AliasTy::Opaque(opaque_ty) => Self::debug_opaque_ty(opaque_ty, fmt),
+        }
+    }
+
+    fn debug_projection_ty(
+        projection_ty: &chalk_ir::ProjectionTy<Self>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        Some(write!(
+            fmt,
+            "projection: {:?} {:?}",
+            projection_ty.associated_ty_id, projection_ty.substitution,
+        ))
+    }
+
+    fn debug_opaque_ty(
+        opaque_ty: &chalk_ir::OpaqueTy<Self>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        Some(write!(fmt, "{:?}", opaque_ty.opaque_ty_id))
+    }
+
+    fn intern_ty(self, ty: chalk_ir::TyKind<Self>) -> Self::InternedType {
+        let flags = ty.compute_flags(self);
+        Box::new(chalk_ir::TyData { kind: ty, flags: flags })
+    }
+
+    fn ty_data<'a>(self, ty: &'a Self::InternedType) -> &'a chalk_ir::TyData<Self> {
+        ty
+    }
+
+    fn intern_lifetime(self, lifetime: chalk_ir::LifetimeData<Self>) -> Self::InternedLifetime {
+        Box::new(lifetime)
+    }
+
+    fn lifetime_data<'a>(
+        self,
+        lifetime: &'a Self::InternedLifetime,
+    ) -> &'a chalk_ir::LifetimeData<Self> {
+        &lifetime
+    }
+
+    fn intern_const(self, constant: chalk_ir::ConstData<Self>) -> Self::InternedConst {
+        Box::new(constant)
+    }
+
+    fn const_data<'a>(self, constant: &'a Self::InternedConst) -> &'a chalk_ir::ConstData<Self> {
+        &constant
+    }
+
+    fn const_eq(
+        self,
+        _ty: &Self::InternedType,
+        c1: &Self::InternedConcreteConst,
+        c2: &Self::InternedConcreteConst,
+    ) -> bool {
+        c1 == c2
+    }
+
+    fn intern_generic_arg(self, data: chalk_ir::GenericArgData<Self>) -> Self::InternedGenericArg {
+        Box::new(data)
+    }
+
+    fn generic_arg_data<'a>(
+        self,
+        data: &'a Self::InternedGenericArg,
+    ) -> &'a chalk_ir::GenericArgData<Self> {
+        &data
+    }
+
+    fn intern_goal(self, goal: chalk_ir::GoalData<Self>) -> Self::InternedGoal {
+        Box::new(goal)
+    }
+
+    fn goal_data<'a>(self, goal: &'a Self::InternedGoal) -> &'a chalk_ir::GoalData<Self> {
+        &goal
+    }
+
+    fn intern_goals<E>(
+        self,
+        data: impl IntoIterator<Item = Result<chalk_ir::Goal<Self>, E>>,
+    ) -> Result<Self::InternedGoals, E> {
+        data.into_iter().collect::<Result<Vec<_>, _>>()
+    }
+
+    fn goals_data<'a>(self, goals: &'a Self::InternedGoals) -> &'a [chalk_ir::Goal<Self>] {
+        goals
+    }
+
+    fn intern_substitution<E>(
+        self,
+        data: impl IntoIterator<Item = Result<chalk_ir::GenericArg<Self>, E>>,
+    ) -> Result<Self::InternedSubstitution, E> {
+        data.into_iter().collect::<Result<Vec<_>, _>>()
+    }
+
+    fn substitution_data<'a>(
+        self,
+        substitution: &'a Self::InternedSubstitution,
+    ) -> &'a [chalk_ir::GenericArg<Self>] {
+        substitution
+    }
+
+    fn intern_program_clause(
+        self,
+        data: chalk_ir::ProgramClauseData<Self>,
+    ) -> Self::InternedProgramClause {
+        Box::new(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> {
+        data.into_iter().collect::<Result<Vec<_>, _>>()
+    }
+
+    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> {
+        data.into_iter().collect::<Result<Vec<_>, _>>()
+    }
+
+    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> {
+        data.into_iter().collect::<Result<Vec<_>, _>>()
+    }
+
+    fn variable_kinds_data<'a>(
+        self,
+        parameter_kinds: &'a Self::InternedVariableKinds,
+    ) -> &'a [chalk_ir::VariableKind<Self>] {
+        parameter_kinds
+    }
+
+    fn intern_canonical_var_kinds<E>(
+        self,
+        data: impl IntoIterator<Item = Result<chalk_ir::CanonicalVarKind<Self>, E>>,
+    ) -> Result<Self::InternedCanonicalVarKinds, E> {
+        data.into_iter().collect::<Result<Vec<_>, _>>()
+    }
+
+    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::<Result<Vec<_>, _>>()
+    }
+
+    fn constraints_data<'a>(
+        self,
+        constraints: &'a Self::InternedConstraints,
+    ) -> &'a [chalk_ir::InEnvironment<chalk_ir::Constraint<Self>>] {
+        constraints
+    }
+
+    fn intern_variances<E>(
+        self,
+        data: impl IntoIterator<Item = Result<chalk_ir::Variance, E>>,
+    ) -> Result<Self::InternedVariances, E> {
+        data.into_iter().collect::<Result<Vec<_>, _>>()
+    }
+
+    fn variances_data<'a>(
+        self,
+        variances: &'a Self::InternedVariances,
+    ) -> &'a [chalk_ir::Variance] {
+        variances
+    }
+}
+
+impl<'tcx> chalk_ir::interner::HasInterner for RustInterner<'tcx> {
+    type Interner = Self;
+}
+
+/// A chalk environment and goal.
+#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, HashStable, TypeFoldable, TypeVisitable)]
+pub struct ChalkEnvironmentAndGoal<'tcx> {
+    pub environment: &'tcx ty::List<ty::Predicate<'tcx>>,
+    pub goal: ty::Predicate<'tcx>,
+}
+
+impl<'tcx> fmt::Display for ChalkEnvironmentAndGoal<'tcx> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "environment: {:?}, goal: {}", self.environment, self.goal)
+    }
+}