rust/crates/ra_hir/src/ty/traits/chalk.rs
2019-05-04 18:18:30 +02:00

329 lines
12 KiB
Rust

//! Conversion code from/to Chalk.
use std::sync::Arc;
use chalk_ir::{TypeId, ImplId, TypeKindId, ProjectionTy, Parameter, Identifier, cast::Cast, PlaceholderIndex, UniverseIndex, TypeName};
use chalk_rust_ir::{AssociatedTyDatum, TraitDatum, StructDatum, ImplDatum};
use ra_db::salsa::{InternId, InternKey};
use crate::{
Trait, HasGenericParams, ImplBlock,
db::HirDatabase,
ty::{TraitRef, Ty, ApplicationTy, TypeCtor, Substs},
};
use super::ChalkContext;
pub(super) trait ToChalk {
type Chalk;
fn to_chalk(self, db: &impl HirDatabase) -> Self::Chalk;
fn from_chalk(db: &impl HirDatabase, chalk: Self::Chalk) -> Self;
}
pub(super) fn from_chalk<T, ChalkT>(db: &impl HirDatabase, chalk: ChalkT) -> T
where
T: ToChalk<Chalk = ChalkT>,
{
T::from_chalk(db, chalk)
}
impl ToChalk for Ty {
type Chalk = chalk_ir::Ty;
fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::Ty {
match self {
Ty::Apply(apply_ty) => chalk_ir::Ty::Apply(apply_ty.to_chalk(db)),
Ty::Param { idx, .. } => {
PlaceholderIndex { ui: UniverseIndex::ROOT, idx: idx as usize }.to_ty()
}
Ty::Bound(idx) => chalk_ir::Ty::BoundVar(idx as usize),
Ty::Infer(_infer_ty) => panic!("uncanonicalized infer ty"),
Ty::Unknown => unimplemented!(), // TODO turn into placeholder?
}
}
fn from_chalk(db: &impl HirDatabase, chalk: chalk_ir::Ty) -> Self {
match chalk {
chalk_ir::Ty::Apply(apply_ty) => {
match apply_ty.name {
// FIXME handle TypeKindId::Trait/Type here
TypeName::TypeKindId(_) => Ty::Apply(from_chalk(db, apply_ty)),
TypeName::AssociatedType(_) => unimplemented!(),
TypeName::Placeholder(idx) => {
assert_eq!(idx.ui, UniverseIndex::ROOT);
Ty::Param { idx: idx.idx as u32, name: crate::Name::missing() }
}
}
}
chalk_ir::Ty::Projection(_) => unimplemented!(),
chalk_ir::Ty::UnselectedProjection(_) => unimplemented!(),
chalk_ir::Ty::ForAll(_) => unimplemented!(),
chalk_ir::Ty::BoundVar(idx) => Ty::Bound(idx as u32),
chalk_ir::Ty::InferenceVar(_iv) => panic!("unexpected chalk infer ty"),
}
}
}
impl ToChalk for ApplicationTy {
type Chalk = chalk_ir::ApplicationTy;
fn to_chalk(self: ApplicationTy, db: &impl HirDatabase) -> chalk_ir::ApplicationTy {
let struct_id = self.ctor.to_chalk(db);
let name = TypeName::TypeKindId(struct_id.into());
let parameters = self.parameters.to_chalk(db);
chalk_ir::ApplicationTy { name, parameters }
}
fn from_chalk(db: &impl HirDatabase, apply_ty: chalk_ir::ApplicationTy) -> ApplicationTy {
let ctor = match apply_ty.name {
TypeName::TypeKindId(TypeKindId::StructId(struct_id)) => from_chalk(db, struct_id),
TypeName::TypeKindId(_) => unimplemented!(),
TypeName::Placeholder(_) => unimplemented!(),
TypeName::AssociatedType(_) => unimplemented!(),
};
let parameters = from_chalk(db, apply_ty.parameters);
ApplicationTy { ctor, parameters }
}
}
impl ToChalk for Substs {
type Chalk = Vec<chalk_ir::Parameter>;
fn to_chalk(self, db: &impl HirDatabase) -> Vec<Parameter> {
self.iter().map(|ty| ty.clone().to_chalk(db).cast()).collect()
}
fn from_chalk(db: &impl HirDatabase, parameters: Vec<chalk_ir::Parameter>) -> Substs {
parameters
.into_iter()
.map(|p| match p {
chalk_ir::Parameter(chalk_ir::ParameterKind::Ty(ty)) => from_chalk(db, ty),
chalk_ir::Parameter(chalk_ir::ParameterKind::Lifetime(_)) => unimplemented!(),
})
.collect::<Vec<_>>()
.into()
}
}
impl ToChalk for TraitRef {
type Chalk = chalk_ir::TraitRef;
fn to_chalk(self: TraitRef, db: &impl HirDatabase) -> chalk_ir::TraitRef {
let trait_id = self.trait_.to_chalk(db);
let parameters = self.substs.to_chalk(db);
chalk_ir::TraitRef { trait_id, parameters }
}
fn from_chalk(db: &impl HirDatabase, trait_ref: chalk_ir::TraitRef) -> Self {
let trait_ = from_chalk(db, trait_ref.trait_id);
let substs = from_chalk(db, trait_ref.parameters);
TraitRef { trait_, substs }
}
}
impl ToChalk for Trait {
type Chalk = chalk_ir::TraitId;
fn to_chalk(self, _db: &impl HirDatabase) -> chalk_ir::TraitId {
self.id.into()
}
fn from_chalk(_db: &impl HirDatabase, trait_id: chalk_ir::TraitId) -> Trait {
Trait { id: trait_id.into() }
}
}
impl ToChalk for TypeCtor {
type Chalk = chalk_ir::StructId;
fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::StructId {
db.intern_type_ctor(self).into()
}
fn from_chalk(db: &impl HirDatabase, struct_id: chalk_ir::StructId) -> TypeCtor {
db.lookup_intern_type_ctor(struct_id.into())
}
}
impl ToChalk for ImplBlock {
type Chalk = chalk_ir::ImplId;
fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::ImplId {
db.intern_impl_block(self).into()
}
fn from_chalk(db: &impl HirDatabase, impl_id: chalk_ir::ImplId) -> ImplBlock {
db.lookup_intern_impl_block(impl_id.into())
}
}
fn make_binders<T>(value: T, num_vars: usize) -> chalk_ir::Binders<T> {
chalk_ir::Binders {
value,
binders: std::iter::repeat(chalk_ir::ParameterKind::Ty(())).take(num_vars).collect(),
}
}
impl<'a, DB> chalk_solve::RustIrDatabase for ChalkContext<'a, DB>
where
DB: HirDatabase,
{
fn associated_ty_data(&self, _ty: TypeId) -> Arc<AssociatedTyDatum> {
unimplemented!()
}
fn trait_datum(&self, trait_id: chalk_ir::TraitId) -> Arc<TraitDatum> {
eprintln!("trait_datum {:?}", trait_id);
let trait_: Trait = from_chalk(self.db, trait_id);
let generic_params = trait_.generic_params(self.db);
let bound_vars = Substs::bound_vars(&generic_params);
let trait_ref = trait_.trait_ref(self.db).subst(&bound_vars).to_chalk(self.db);
let flags = chalk_rust_ir::TraitFlags {
// FIXME set these flags correctly
auto: false,
marker: false,
upstream: trait_.module(self.db).krate(self.db) != Some(self.krate),
fundamental: false,
};
let where_clauses = Vec::new(); // FIXME add where clauses
let trait_datum_bound = chalk_rust_ir::TraitDatumBound { trait_ref, where_clauses, flags };
let trait_datum = TraitDatum { binders: make_binders(trait_datum_bound, bound_vars.len()) };
Arc::new(trait_datum)
}
fn struct_datum(&self, struct_id: chalk_ir::StructId) -> Arc<StructDatum> {
eprintln!("struct_datum {:?}", struct_id);
let type_ctor = from_chalk(self.db, struct_id);
// TODO might be nicer if we can create a fake GenericParams for the TypeCtor
let (num_params, upstream) = match type_ctor {
TypeCtor::Bool
| TypeCtor::Char
| TypeCtor::Int(_)
| TypeCtor::Float(_)
| TypeCtor::Never
| TypeCtor::Str => (0, true),
TypeCtor::Slice | TypeCtor::Array | TypeCtor::RawPtr(_) | TypeCtor::Ref(_) => (1, true),
TypeCtor::FnPtr | TypeCtor::Tuple => unimplemented!(), // FIXME tuples and FnPtr are currently variadic... we need to make the parameter number explicit
TypeCtor::FnDef(_) => unimplemented!(),
TypeCtor::Adt(adt) => {
let generic_params = adt.generic_params(self.db);
(
generic_params.count_params_including_parent(),
adt.krate(self.db) != Some(self.krate),
)
}
};
let flags = chalk_rust_ir::StructFlags {
upstream,
// FIXME set fundamental flag correctly
fundamental: false,
};
let where_clauses = Vec::new(); // FIXME add where clauses
let ty = ApplicationTy {
ctor: type_ctor,
parameters: (0..num_params).map(|i| Ty::Bound(i as u32)).collect::<Vec<_>>().into(),
};
let struct_datum_bound = chalk_rust_ir::StructDatumBound {
self_ty: ty.to_chalk(self.db),
fields: Vec::new(), // FIXME add fields (only relevant for auto traits)
where_clauses,
flags,
};
let struct_datum = StructDatum { binders: make_binders(struct_datum_bound, num_params) };
Arc::new(struct_datum)
}
fn impl_datum(&self, impl_id: ImplId) -> Arc<ImplDatum> {
eprintln!("impl_datum {:?}", impl_id);
let impl_block: ImplBlock = from_chalk(self.db, impl_id);
let generic_params = impl_block.generic_params(self.db);
let bound_vars = Substs::bound_vars(&generic_params);
let trait_ref = impl_block
.target_trait_ref(self.db)
.expect("FIXME handle unresolved impl block trait ref")
.subst(&bound_vars);
let impl_type = if impl_block.module().krate(self.db) == Some(self.krate) {
chalk_rust_ir::ImplType::Local
} else {
chalk_rust_ir::ImplType::External
};
let impl_datum_bound = chalk_rust_ir::ImplDatumBound {
// FIXME handle negative impls (impl !Sync for Foo)
trait_ref: chalk_rust_ir::PolarizedTraitRef::Positive(trait_ref.to_chalk(self.db)),
where_clauses: Vec::new(), // FIXME add where clauses
associated_ty_values: Vec::new(), // FIXME add associated type values
impl_type,
};
let impl_datum = ImplDatum { binders: make_binders(impl_datum_bound, bound_vars.len()) };
Arc::new(impl_datum)
}
fn impls_for_trait(&self, trait_id: chalk_ir::TraitId) -> Vec<ImplId> {
eprintln!("impls_for_trait {:?}", trait_id);
let trait_ = from_chalk(self.db, trait_id);
self.db
.impls_for_trait(self.krate, trait_)
.iter()
// FIXME temporary hack -- as long as we're not lowering where clauses
// correctly, ignore impls with them completely so as to not treat
// impl<T> Trait for T where T: ... as a blanket impl on all types
.filter(|impl_block| impl_block.generic_params(self.db).where_predicates.is_empty())
.map(|impl_block| impl_block.to_chalk(self.db))
.collect()
}
fn impl_provided_for(
&self,
auto_trait_id: chalk_ir::TraitId,
struct_id: chalk_ir::StructId,
) -> bool {
eprintln!("impl_provided_for {:?}, {:?}", auto_trait_id, struct_id);
false // FIXME
}
fn type_name(&self, _id: TypeKindId) -> Identifier {
unimplemented!()
}
fn split_projection<'p>(
&self,
projection: &'p ProjectionTy,
) -> (Arc<AssociatedTyDatum>, &'p [Parameter], &'p [Parameter]) {
eprintln!("split_projection {:?}", projection);
unimplemented!()
}
}
fn id_from_chalk<T: InternKey>(chalk_id: chalk_ir::RawId) -> T {
T::from_intern_id(InternId::from(chalk_id.index))
}
fn id_to_chalk<T: InternKey>(salsa_id: T) -> chalk_ir::RawId {
chalk_ir::RawId { index: salsa_id.as_intern_id().as_u32() }
}
impl From<chalk_ir::TraitId> for crate::ids::TraitId {
fn from(trait_id: chalk_ir::TraitId) -> Self {
id_from_chalk(trait_id.0)
}
}
impl From<crate::ids::TraitId> for chalk_ir::TraitId {
fn from(trait_id: crate::ids::TraitId) -> Self {
chalk_ir::TraitId(id_to_chalk(trait_id))
}
}
impl From<chalk_ir::StructId> for crate::ids::TypeCtorId {
fn from(struct_id: chalk_ir::StructId) -> Self {
id_from_chalk(struct_id.0)
}
}
impl From<crate::ids::TypeCtorId> for chalk_ir::StructId {
fn from(type_ctor_id: crate::ids::TypeCtorId) -> Self {
chalk_ir::StructId(id_to_chalk(type_ctor_id))
}
}
impl From<chalk_ir::ImplId> for crate::ids::GlobalImplId {
fn from(impl_id: chalk_ir::ImplId) -> Self {
id_from_chalk(impl_id.0)
}
}
impl From<crate::ids::GlobalImplId> for chalk_ir::ImplId {
fn from(impl_id: crate::ids::GlobalImplId) -> Self {
chalk_ir::ImplId(id_to_chalk(impl_id))
}
}