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//! Provides the `RustIrDatabase` implementation for `chalk-solve`
//!
//! The purpose of the `chalk_solve::RustIrDatabase` is to get data about
//! specific types, such as bounds, where clauses, or fields. This file contains
//! the minimal logic to assemble the types for `chalk-solve` by calling out to
//! either the `TyCtxt` (for information about types) or
//! `crate::chalk::lowering` (to lower rustc types into Chalk types).
use rustc_middle::traits::ChalkRustInterner as RustInterner;
use rustc_middle::ty::{self, AssocKind, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable};
use rustc_middle::ty::{InternalSubsts, SubstsRef};
use rustc_target::abi::{Integer, IntegerType};
use rustc_ast::ast;
use rustc_hir::def_id::DefId;
use rustc_span::symbol::sym;
use std::fmt;
use std::sync::Arc;
use crate::chalk::lowering::LowerInto;
pub struct RustIrDatabase<'tcx> {
pub(crate) interner: RustInterner<'tcx>,
}
impl fmt::Debug for RustIrDatabase<'_> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "RustIrDatabase")
}
}
impl<'tcx> RustIrDatabase<'tcx> {
fn where_clauses_for(
&self,
def_id: DefId,
bound_vars: SubstsRef<'tcx>,
) -> Vec<chalk_ir::QuantifiedWhereClause<RustInterner<'tcx>>> {
self.interner
.tcx
.predicates_defined_on(def_id)
.instantiate_own(self.interner.tcx, bound_vars)
.filter_map(|(wc, _)| LowerInto::lower_into(wc, self.interner))
.collect()
}
fn bounds_for<T>(&self, def_id: DefId, bound_vars: SubstsRef<'tcx>) -> Vec<T>
where
ty::Predicate<'tcx>: LowerInto<'tcx, std::option::Option<T>>,
{
self.interner
.tcx
.explicit_item_bounds(def_id)
.subst_iter_copied(self.interner.tcx, &bound_vars)
.filter_map(|(bound, _)| LowerInto::<Option<_>>::lower_into(bound, self.interner))
.collect()
}
}
impl<'tcx> chalk_solve::RustIrDatabase<RustInterner<'tcx>> for RustIrDatabase<'tcx> {
fn interner(&self) -> RustInterner<'tcx> {
self.interner
}
fn associated_ty_data(
&self,
assoc_type_id: chalk_ir::AssocTypeId<RustInterner<'tcx>>,
) -> Arc<chalk_solve::rust_ir::AssociatedTyDatum<RustInterner<'tcx>>> {
let def_id = assoc_type_id.0;
let assoc_item = self.interner.tcx.associated_item(def_id);
let Some(trait_def_id) = assoc_item.trait_container(self.interner.tcx) else {
unimplemented!("Not possible??");
};
match assoc_item.kind {
AssocKind::Type => {}
_ => unimplemented!("Not possible??"),
}
let bound_vars = bound_vars_for_item(self.interner.tcx, def_id);
let binders = binders_for(self.interner, bound_vars);
let where_clauses = self.where_clauses_for(def_id, bound_vars);
let bounds = self.bounds_for(def_id, bound_vars);
Arc::new(chalk_solve::rust_ir::AssociatedTyDatum {
trait_id: chalk_ir::TraitId(trait_def_id),
id: assoc_type_id,
name: (),
binders: chalk_ir::Binders::new(
binders,
chalk_solve::rust_ir::AssociatedTyDatumBound { bounds, where_clauses },
),
})
}
fn trait_datum(
&self,
trait_id: chalk_ir::TraitId<RustInterner<'tcx>>,
) -> Arc<chalk_solve::rust_ir::TraitDatum<RustInterner<'tcx>>> {
use chalk_solve::rust_ir::WellKnownTrait::*;
let def_id = trait_id.0;
let trait_def = self.interner.tcx.trait_def(def_id);
let bound_vars = bound_vars_for_item(self.interner.tcx, def_id);
let binders = binders_for(self.interner, bound_vars);
let where_clauses = self.where_clauses_for(def_id, bound_vars);
let associated_ty_ids: Vec<_> = self
.interner
.tcx
.associated_items(def_id)
.in_definition_order()
.filter(|i| i.kind == AssocKind::Type)
.map(|i| chalk_ir::AssocTypeId(i.def_id))
.collect();
let lang_items = self.interner.tcx.lang_items();
let well_known = if lang_items.sized_trait() == Some(def_id) {
Some(Sized)
} else if lang_items.copy_trait() == Some(def_id) {
Some(Copy)
} else if lang_items.clone_trait() == Some(def_id) {
Some(Clone)
} else if lang_items.drop_trait() == Some(def_id) {
Some(Drop)
} else if lang_items.fn_trait() == Some(def_id) {
Some(Fn)
} else if lang_items.fn_once_trait() == Some(def_id) {
Some(FnOnce)
} else if lang_items.fn_mut_trait() == Some(def_id) {
Some(FnMut)
} else if lang_items.unsize_trait() == Some(def_id) {
Some(Unsize)
} else if lang_items.unpin_trait() == Some(def_id) {
Some(Unpin)
} else if lang_items.coerce_unsized_trait() == Some(def_id) {
Some(CoerceUnsized)
} else if lang_items.dispatch_from_dyn_trait() == Some(def_id) {
Some(DispatchFromDyn)
} else if lang_items.tuple_trait() == Some(def_id) {
Some(Tuple)
} else {
None
};
Arc::new(chalk_solve::rust_ir::TraitDatum {
id: trait_id,
binders: chalk_ir::Binders::new(
binders,
chalk_solve::rust_ir::TraitDatumBound { where_clauses },
),
flags: chalk_solve::rust_ir::TraitFlags {
auto: trait_def.has_auto_impl,
marker: trait_def.is_marker,
upstream: !def_id.is_local(),
fundamental: self.interner.tcx.has_attr(def_id, sym::fundamental),
non_enumerable: true,
coinductive: false,
},
associated_ty_ids,
well_known,
})
}
fn adt_datum(
&self,
adt_id: chalk_ir::AdtId<RustInterner<'tcx>>,
) -> Arc<chalk_solve::rust_ir::AdtDatum<RustInterner<'tcx>>> {
let adt_def = adt_id.0;
let bound_vars = bound_vars_for_item(self.interner.tcx, adt_def.did());
let binders = binders_for(self.interner, bound_vars);
let where_clauses = self.where_clauses_for(adt_def.did(), bound_vars);
let variants: Vec<_> = adt_def
.variants()
.iter()
.map(|variant| chalk_solve::rust_ir::AdtVariantDatum {
fields: variant
.fields
.iter()
.map(|field| field.ty(self.interner.tcx, bound_vars).lower_into(self.interner))
.collect(),
})
.collect();
Arc::new(chalk_solve::rust_ir::AdtDatum {
id: adt_id,
binders: chalk_ir::Binders::new(
binders,
chalk_solve::rust_ir::AdtDatumBound { variants, where_clauses },
),
flags: chalk_solve::rust_ir::AdtFlags {
upstream: !adt_def.did().is_local(),
fundamental: adt_def.is_fundamental(),
phantom_data: adt_def.is_phantom_data(),
},
kind: match adt_def.adt_kind() {
ty::AdtKind::Struct => chalk_solve::rust_ir::AdtKind::Struct,
ty::AdtKind::Union => chalk_solve::rust_ir::AdtKind::Union,
ty::AdtKind::Enum => chalk_solve::rust_ir::AdtKind::Enum,
},
})
}
fn adt_repr(
&self,
adt_id: chalk_ir::AdtId<RustInterner<'tcx>>,
) -> Arc<chalk_solve::rust_ir::AdtRepr<RustInterner<'tcx>>> {
let adt_def = adt_id.0;
let int = |i| chalk_ir::TyKind::Scalar(chalk_ir::Scalar::Int(i)).intern(self.interner);
let uint = |i| chalk_ir::TyKind::Scalar(chalk_ir::Scalar::Uint(i)).intern(self.interner);
Arc::new(chalk_solve::rust_ir::AdtRepr {
c: adt_def.repr().c(),
packed: adt_def.repr().packed(),
int: adt_def.repr().int.map(|i| match i {
IntegerType::Pointer(true) => int(chalk_ir::IntTy::Isize),
IntegerType::Pointer(false) => uint(chalk_ir::UintTy::Usize),
IntegerType::Fixed(i, true) => match i {
Integer::I8 => int(chalk_ir::IntTy::I8),
Integer::I16 => int(chalk_ir::IntTy::I16),
Integer::I32 => int(chalk_ir::IntTy::I32),
Integer::I64 => int(chalk_ir::IntTy::I64),
Integer::I128 => int(chalk_ir::IntTy::I128),
},
IntegerType::Fixed(i, false) => match i {
Integer::I8 => uint(chalk_ir::UintTy::U8),
Integer::I16 => uint(chalk_ir::UintTy::U16),
Integer::I32 => uint(chalk_ir::UintTy::U32),
Integer::I64 => uint(chalk_ir::UintTy::U64),
Integer::I128 => uint(chalk_ir::UintTy::U128),
},
}),
})
}
fn adt_size_align(
&self,
adt_id: chalk_ir::AdtId<RustInterner<'tcx>>,
) -> Arc<chalk_solve::rust_ir::AdtSizeAlign> {
let tcx = self.interner.tcx;
let did = adt_id.0.did();
// Grab the ADT and the param we might need to calculate its layout
let param_env = tcx.param_env(did);
let adt_ty = tcx.type_of(did).subst_identity();
// The ADT is a 1-zst if it's a ZST and its alignment is 1.
// Mark the ADT as _not_ a 1-zst if there was a layout error.
let one_zst = if let Ok(layout) = tcx.layout_of(param_env.and(adt_ty)) {
layout.is_zst() && layout.align.abi.bytes() == 1
} else {
false
};
Arc::new(chalk_solve::rust_ir::AdtSizeAlign::from_one_zst(one_zst))
}
fn fn_def_datum(
&self,
fn_def_id: chalk_ir::FnDefId<RustInterner<'tcx>>,
) -> Arc<chalk_solve::rust_ir::FnDefDatum<RustInterner<'tcx>>> {
let def_id = fn_def_id.0;
let bound_vars = bound_vars_for_item(self.interner.tcx, def_id);
let binders = binders_for(self.interner, bound_vars);
let where_clauses = self.where_clauses_for(def_id, bound_vars);
let sig = self.interner.tcx.fn_sig(def_id);
let (inputs_and_output, iobinders, _) = crate::chalk::lowering::collect_bound_vars(
self.interner,
self.interner.tcx,
sig.map_bound(|s| s.inputs_and_output()).subst(self.interner.tcx, bound_vars),
);
let argument_types = inputs_and_output[..inputs_and_output.len() - 1]
.iter()
.map(|t| sig.rebind(*t).subst(self.interner.tcx, &bound_vars).lower_into(self.interner))
.collect();
let return_type = sig
.rebind(inputs_and_output[inputs_and_output.len() - 1])
.subst(self.interner.tcx, &bound_vars)
.lower_into(self.interner);
let bound = chalk_solve::rust_ir::FnDefDatumBound {
inputs_and_output: chalk_ir::Binders::new(
iobinders,
chalk_solve::rust_ir::FnDefInputsAndOutputDatum { argument_types, return_type },
),
where_clauses,
};
Arc::new(chalk_solve::rust_ir::FnDefDatum {
id: fn_def_id,
sig: sig.skip_binder().lower_into(self.interner),
binders: chalk_ir::Binders::new(binders, bound),
})
}
fn impl_datum(
&self,
impl_id: chalk_ir::ImplId<RustInterner<'tcx>>,
) -> Arc<chalk_solve::rust_ir::ImplDatum<RustInterner<'tcx>>> {
let def_id = impl_id.0;
let bound_vars = bound_vars_for_item(self.interner.tcx, def_id);
let binders = binders_for(self.interner, bound_vars);
let trait_ref = self.interner.tcx.impl_trait_ref(def_id).expect("not an impl");
let trait_ref = trait_ref.subst(self.interner.tcx, bound_vars);
let where_clauses = self.where_clauses_for(def_id, bound_vars);
let value = chalk_solve::rust_ir::ImplDatumBound {
trait_ref: trait_ref.lower_into(self.interner),
where_clauses,
};
let associated_ty_value_ids: Vec<_> = self
.interner
.tcx
.associated_items(def_id)
.in_definition_order()
.filter(|i| i.kind == AssocKind::Type)
.map(|i| chalk_solve::rust_ir::AssociatedTyValueId(i.def_id))
.collect();
Arc::new(chalk_solve::rust_ir::ImplDatum {
polarity: self.interner.tcx.impl_polarity(def_id).lower_into(self.interner),
binders: chalk_ir::Binders::new(binders, value),
impl_type: chalk_solve::rust_ir::ImplType::Local,
associated_ty_value_ids,
})
}
fn impls_for_trait(
&self,
trait_id: chalk_ir::TraitId<RustInterner<'tcx>>,
parameters: &[chalk_ir::GenericArg<RustInterner<'tcx>>],
_binders: &chalk_ir::CanonicalVarKinds<RustInterner<'tcx>>,
) -> Vec<chalk_ir::ImplId<RustInterner<'tcx>>> {
let def_id = trait_id.0;
// FIXME(chalk): use TraitDef::for_each_relevant_impl, but that will
// require us to be able to interconvert `Ty<'tcx>`, and we're
// not there yet.
let all_impls = self.interner.tcx.all_impls(def_id);
let matched_impls = all_impls.filter(|impl_def_id| {
use chalk_ir::could_match::CouldMatch;
let trait_ref = self.interner.tcx.impl_trait_ref(*impl_def_id).unwrap();
let bound_vars = bound_vars_for_item(self.interner.tcx, *impl_def_id);
let self_ty = trait_ref.map_bound(|t| t.self_ty());
let self_ty = self_ty.subst(self.interner.tcx, bound_vars);
let lowered_ty = self_ty.lower_into(self.interner);
parameters[0].assert_ty_ref(self.interner).could_match(
self.interner,
self.unification_database(),
&lowered_ty,
)
});
let impls = matched_impls.map(chalk_ir::ImplId).collect();
impls
}
fn impl_provided_for(
&self,
auto_trait_id: chalk_ir::TraitId<RustInterner<'tcx>>,
chalk_ty: &chalk_ir::TyKind<RustInterner<'tcx>>,
) -> bool {
use chalk_ir::Scalar::*;
use chalk_ir::TyKind::*;
let trait_def_id = auto_trait_id.0;
let all_impls = self.interner.tcx.all_impls(trait_def_id);
for impl_def_id in all_impls {
let trait_ref = self.interner.tcx.impl_trait_ref(impl_def_id).unwrap().subst_identity();
let self_ty = trait_ref.self_ty();
let provides = match (self_ty.kind(), chalk_ty) {
(&ty::Adt(impl_adt_def, ..), Adt(id, ..)) => impl_adt_def.did() == id.0.did(),
(_, AssociatedType(_ty_id, ..)) => {
// FIXME(chalk): See https://github.com/rust-lang/rust/pull/77152#discussion_r494484774
false
}
(ty::Bool, Scalar(Bool)) => true,
(ty::Char, Scalar(Char)) => true,
(ty::Int(ty1), Scalar(Int(ty2))) => matches!(
(ty1, ty2),
(ty::IntTy::Isize, chalk_ir::IntTy::Isize)
| (ty::IntTy::I8, chalk_ir::IntTy::I8)
| (ty::IntTy::I16, chalk_ir::IntTy::I16)
| (ty::IntTy::I32, chalk_ir::IntTy::I32)
| (ty::IntTy::I64, chalk_ir::IntTy::I64)
| (ty::IntTy::I128, chalk_ir::IntTy::I128)
),
(ty::Uint(ty1), Scalar(Uint(ty2))) => matches!(
(ty1, ty2),
(ty::UintTy::Usize, chalk_ir::UintTy::Usize)
| (ty::UintTy::U8, chalk_ir::UintTy::U8)
| (ty::UintTy::U16, chalk_ir::UintTy::U16)
| (ty::UintTy::U32, chalk_ir::UintTy::U32)
| (ty::UintTy::U64, chalk_ir::UintTy::U64)
| (ty::UintTy::U128, chalk_ir::UintTy::U128)
),
(ty::Float(ty1), Scalar(Float(ty2))) => matches!(
(ty1, ty2),
(ty::FloatTy::F32, chalk_ir::FloatTy::F32)
| (ty::FloatTy::F64, chalk_ir::FloatTy::F64)
),
(&ty::Tuple(substs), Tuple(len, _)) => substs.len() == *len,
(&ty::Array(..), Array(..)) => true,
(&ty::Slice(..), Slice(..)) => true,
(&ty::RawPtr(type_and_mut), Raw(mutability, _)) => {
match (type_and_mut.mutbl, mutability) {
(ast::Mutability::Mut, chalk_ir::Mutability::Mut) => true,
(ast::Mutability::Mut, chalk_ir::Mutability::Not) => false,
(ast::Mutability::Not, chalk_ir::Mutability::Mut) => false,
(ast::Mutability::Not, chalk_ir::Mutability::Not) => true,
}
}
(&ty::Ref(.., mutability1), Ref(mutability2, ..)) => {
match (mutability1, mutability2) {
(ast::Mutability::Mut, chalk_ir::Mutability::Mut) => true,
(ast::Mutability::Mut, chalk_ir::Mutability::Not) => false,
(ast::Mutability::Not, chalk_ir::Mutability::Mut) => false,
(ast::Mutability::Not, chalk_ir::Mutability::Not) => true,
}
}
(
&ty::Alias(ty::Opaque, ty::AliasTy { def_id, .. }),
OpaqueType(opaque_ty_id, ..),
) => def_id == opaque_ty_id.0,
(&ty::FnDef(def_id, ..), FnDef(fn_def_id, ..)) => def_id == fn_def_id.0,
(&ty::Str, Str) => true,
(&ty::Never, Never) => true,
(&ty::Closure(def_id, ..), Closure(closure_id, _)) => def_id == closure_id.0,
(&ty::Foreign(def_id), Foreign(foreign_def_id)) => def_id == foreign_def_id.0,
(&ty::Error(..), Error) => false,
_ => false,
};
if provides {
return true;
}
}
false
}
fn associated_ty_value(
&self,
associated_ty_id: chalk_solve::rust_ir::AssociatedTyValueId<RustInterner<'tcx>>,
) -> Arc<chalk_solve::rust_ir::AssociatedTyValue<RustInterner<'tcx>>> {
let def_id = associated_ty_id.0;
let assoc_item = self.interner.tcx.associated_item(def_id);
let impl_id = assoc_item.container_id(self.interner.tcx);
match assoc_item.kind {
AssocKind::Type => {}
_ => unimplemented!("Not possible??"),
}
let trait_item_id = assoc_item.trait_item_def_id.expect("assoc_ty with no trait version");
let bound_vars = bound_vars_for_item(self.interner.tcx, def_id);
let binders = binders_for(self.interner, bound_vars);
let ty = self
.interner
.tcx
.type_of(def_id)
.subst(self.interner.tcx, bound_vars)
.lower_into(self.interner);
Arc::new(chalk_solve::rust_ir::AssociatedTyValue {
impl_id: chalk_ir::ImplId(impl_id),
associated_ty_id: chalk_ir::AssocTypeId(trait_item_id),
value: chalk_ir::Binders::new(
binders,
chalk_solve::rust_ir::AssociatedTyValueBound { ty },
),
})
}
fn custom_clauses(&self) -> Vec<chalk_ir::ProgramClause<RustInterner<'tcx>>> {
vec![]
}
fn local_impls_to_coherence_check(
&self,
_trait_id: chalk_ir::TraitId<RustInterner<'tcx>>,
) -> Vec<chalk_ir::ImplId<RustInterner<'tcx>>> {
unimplemented!()
}
fn opaque_ty_data(
&self,
opaque_ty_id: chalk_ir::OpaqueTyId<RustInterner<'tcx>>,
) -> Arc<chalk_solve::rust_ir::OpaqueTyDatum<RustInterner<'tcx>>> {
let bound_vars = ty::fold::shift_vars(
self.interner.tcx,
bound_vars_for_item(self.interner.tcx, opaque_ty_id.0),
1,
);
let where_clauses = self.where_clauses_for(opaque_ty_id.0, bound_vars);
let identity_substs = InternalSubsts::identity_for_item(self.interner.tcx, opaque_ty_id.0);
let explicit_item_bounds = self.interner.tcx.explicit_item_bounds(opaque_ty_id.0);
let bounds =
explicit_item_bounds
.subst_iter_copied(self.interner.tcx, &bound_vars)
.map(|(bound, _)| {
bound.fold_with(&mut ReplaceOpaqueTyFolder {
tcx: self.interner.tcx,
opaque_ty_id,
identity_substs,
binder_index: ty::INNERMOST,
})
})
.filter_map(|bound| {
LowerInto::<
Option<chalk_ir::QuantifiedWhereClause<RustInterner<'tcx>>>
>::lower_into(bound, self.interner)
})
.collect();
// Binder for the bound variable representing the concrete impl Trait type.
let existential_binder = chalk_ir::VariableKinds::from1(
self.interner,
chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General),
);
let value = chalk_solve::rust_ir::OpaqueTyDatumBound {
bounds: chalk_ir::Binders::new(existential_binder.clone(), bounds),
where_clauses: chalk_ir::Binders::new(existential_binder, where_clauses),
};
let binders = binders_for(self.interner, bound_vars);
Arc::new(chalk_solve::rust_ir::OpaqueTyDatum {
opaque_ty_id,
bound: chalk_ir::Binders::new(binders, value),
})
}
fn program_clauses_for_env(
&self,
environment: &chalk_ir::Environment<RustInterner<'tcx>>,
) -> chalk_ir::ProgramClauses<RustInterner<'tcx>> {
chalk_solve::program_clauses_for_env(self, environment)
}
fn well_known_trait_id(
&self,
well_known_trait: chalk_solve::rust_ir::WellKnownTrait,
) -> Option<chalk_ir::TraitId<RustInterner<'tcx>>> {
use chalk_solve::rust_ir::WellKnownTrait::*;
let lang_items = self.interner.tcx.lang_items();
let def_id = match well_known_trait {
Sized => lang_items.sized_trait(),
Copy => lang_items.copy_trait(),
Clone => lang_items.clone_trait(),
Drop => lang_items.drop_trait(),
Fn => lang_items.fn_trait(),
FnMut => lang_items.fn_mut_trait(),
FnOnce => lang_items.fn_once_trait(),
Generator => lang_items.gen_trait(),
Unsize => lang_items.unsize_trait(),
Unpin => lang_items.unpin_trait(),
CoerceUnsized => lang_items.coerce_unsized_trait(),
DiscriminantKind => lang_items.discriminant_kind_trait(),
DispatchFromDyn => lang_items.dispatch_from_dyn_trait(),
Tuple => lang_items.tuple_trait(),
};
def_id.map(chalk_ir::TraitId)
}
fn is_object_safe(&self, trait_id: chalk_ir::TraitId<RustInterner<'tcx>>) -> bool {
self.interner.tcx.check_is_object_safe(trait_id.0)
}
fn hidden_opaque_type(
&self,
_id: chalk_ir::OpaqueTyId<RustInterner<'tcx>>,
) -> chalk_ir::Ty<RustInterner<'tcx>> {
// FIXME(chalk): actually get hidden ty
self.interner.tcx.types.unit.lower_into(self.interner)
}
fn closure_kind(
&self,
_closure_id: chalk_ir::ClosureId<RustInterner<'tcx>>,
substs: &chalk_ir::Substitution<RustInterner<'tcx>>,
) -> chalk_solve::rust_ir::ClosureKind {
let kind = &substs.as_slice(self.interner)[substs.len(self.interner) - 3];
match kind.assert_ty_ref(self.interner).kind(self.interner) {
chalk_ir::TyKind::Scalar(chalk_ir::Scalar::Int(int_ty)) => match int_ty {
chalk_ir::IntTy::I8 => chalk_solve::rust_ir::ClosureKind::Fn,
chalk_ir::IntTy::I16 => chalk_solve::rust_ir::ClosureKind::FnMut,
chalk_ir::IntTy::I32 => chalk_solve::rust_ir::ClosureKind::FnOnce,
_ => bug!("bad closure kind"),
},
_ => bug!("bad closure kind"),
}
}
fn closure_inputs_and_output(
&self,
_closure_id: chalk_ir::ClosureId<RustInterner<'tcx>>,
substs: &chalk_ir::Substitution<RustInterner<'tcx>>,
) -> chalk_ir::Binders<chalk_solve::rust_ir::FnDefInputsAndOutputDatum<RustInterner<'tcx>>>
{
let sig = &substs.as_slice(self.interner)[substs.len(self.interner) - 2];
match sig.assert_ty_ref(self.interner).kind(self.interner) {
chalk_ir::TyKind::Function(f) => {
let substitution = f.substitution.0.as_slice(self.interner);
let return_type = substitution.last().unwrap().assert_ty_ref(self.interner).clone();
// Closure arguments are tupled
let argument_tuple = substitution[0].assert_ty_ref(self.interner);
let argument_types = match argument_tuple.kind(self.interner) {
chalk_ir::TyKind::Tuple(_len, substitution) => substitution
.iter(self.interner)
.map(|arg| arg.assert_ty_ref(self.interner))
.cloned()
.collect(),
_ => bug!("Expecting closure FnSig args to be tupled."),
};
chalk_ir::Binders::new(
chalk_ir::VariableKinds::from_iter(
self.interner,
(0..f.num_binders).map(|_| chalk_ir::VariableKind::Lifetime),
),
chalk_solve::rust_ir::FnDefInputsAndOutputDatum { argument_types, return_type },
)
}
_ => panic!("Invalid sig."),
}
}
fn closure_upvars(
&self,
_closure_id: chalk_ir::ClosureId<RustInterner<'tcx>>,
substs: &chalk_ir::Substitution<RustInterner<'tcx>>,
) -> chalk_ir::Binders<chalk_ir::Ty<RustInterner<'tcx>>> {
let inputs_and_output = self.closure_inputs_and_output(_closure_id, substs);
let tuple = substs.as_slice(self.interner).last().unwrap().assert_ty_ref(self.interner);
inputs_and_output.map_ref(|_| tuple.clone())
}
fn closure_fn_substitution(
&self,
_closure_id: chalk_ir::ClosureId<RustInterner<'tcx>>,
substs: &chalk_ir::Substitution<RustInterner<'tcx>>,
) -> chalk_ir::Substitution<RustInterner<'tcx>> {
let substitution = &substs.as_slice(self.interner)[0..substs.len(self.interner) - 3];
chalk_ir::Substitution::from_iter(self.interner, substitution)
}
fn generator_datum(
&self,
_generator_id: chalk_ir::GeneratorId<RustInterner<'tcx>>,
) -> Arc<chalk_solve::rust_ir::GeneratorDatum<RustInterner<'tcx>>> {
unimplemented!()
}
fn generator_witness_datum(
&self,
_generator_id: chalk_ir::GeneratorId<RustInterner<'tcx>>,
) -> Arc<chalk_solve::rust_ir::GeneratorWitnessDatum<RustInterner<'tcx>>> {
unimplemented!()
}
fn unification_database(&self) -> &dyn chalk_ir::UnificationDatabase<RustInterner<'tcx>> {
self
}
fn discriminant_type(
&self,
_: chalk_ir::Ty<RustInterner<'tcx>>,
) -> chalk_ir::Ty<RustInterner<'tcx>> {
unimplemented!()
}
}
impl<'tcx> chalk_ir::UnificationDatabase<RustInterner<'tcx>> for RustIrDatabase<'tcx> {
fn fn_def_variance(
&self,
def_id: chalk_ir::FnDefId<RustInterner<'tcx>>,
) -> chalk_ir::Variances<RustInterner<'tcx>> {
let variances = self.interner.tcx.variances_of(def_id.0);
chalk_ir::Variances::from_iter(
self.interner,
variances.iter().map(|v| v.lower_into(self.interner)),
)
}
fn adt_variance(
&self,
adt_id: chalk_ir::AdtId<RustInterner<'tcx>>,
) -> chalk_ir::Variances<RustInterner<'tcx>> {
let variances = self.interner.tcx.variances_of(adt_id.0.did());
chalk_ir::Variances::from_iter(
self.interner,
variances.iter().map(|v| v.lower_into(self.interner)),
)
}
}
/// Creates an `InternalSubsts` that maps each generic parameter to a higher-ranked
/// var bound at index `0`. For types, we use a `BoundVar` index equal to
/// the type parameter index. For regions, we use the `BoundRegionKind::BrNamed`
/// variant (which has a `DefId`).
fn bound_vars_for_item(tcx: TyCtxt<'_>, def_id: DefId) -> SubstsRef<'_> {
InternalSubsts::for_item(tcx, def_id, |param, substs| match param.kind {
ty::GenericParamDefKind::Type { .. } => tcx
.mk_bound(
ty::INNERMOST,
ty::BoundTy {
var: ty::BoundVar::from(param.index),
kind: ty::BoundTyKind::Param(param.def_id, param.name),
},
)
.into(),
ty::GenericParamDefKind::Lifetime => {
let br = ty::BoundRegion {
var: ty::BoundVar::from_usize(substs.len()),
kind: ty::BrAnon(None),
};
tcx.mk_re_late_bound(ty::INNERMOST, br).into()
}
ty::GenericParamDefKind::Const { .. } => tcx
.mk_const(
ty::ConstKind::Bound(ty::INNERMOST, ty::BoundVar::from(param.index)),
tcx.type_of(param.def_id).subst_identity(),
)
.into(),
})
}
fn binders_for<'tcx>(
interner: RustInterner<'tcx>,
bound_vars: SubstsRef<'tcx>,
) -> chalk_ir::VariableKinds<RustInterner<'tcx>> {
chalk_ir::VariableKinds::from_iter(
interner,
bound_vars.iter().map(|arg| match arg.unpack() {
ty::subst::GenericArgKind::Lifetime(_re) => chalk_ir::VariableKind::Lifetime,
ty::subst::GenericArgKind::Type(_ty) => {
chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General)
}
ty::subst::GenericArgKind::Const(c) => {
chalk_ir::VariableKind::Const(c.ty().lower_into(interner))
}
}),
)
}
struct ReplaceOpaqueTyFolder<'tcx> {
tcx: TyCtxt<'tcx>,
opaque_ty_id: chalk_ir::OpaqueTyId<RustInterner<'tcx>>,
identity_substs: SubstsRef<'tcx>,
binder_index: ty::DebruijnIndex,
}
impl<'tcx> ty::TypeFolder<TyCtxt<'tcx>> for ReplaceOpaqueTyFolder<'tcx> {
fn interner(&self) -> TyCtxt<'tcx> {
self.tcx
}
fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
&mut self,
t: ty::Binder<'tcx, T>,
) -> ty::Binder<'tcx, T> {
self.binder_index.shift_in(1);
let t = t.super_fold_with(self);
self.binder_index.shift_out(1);
t
}
fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> {
if let ty::Alias(ty::Opaque, ty::AliasTy { def_id, substs, .. }) = *ty.kind() {
if def_id == self.opaque_ty_id.0 && substs == self.identity_substs {
return self
.tcx
.mk_bound(self.binder_index, ty::BoundTy::from(ty::BoundVar::from_u32(0)));
}
}
ty
}
}