rust/crates/hir-ty/src/chalk_ext.rs

371 lines
15 KiB
Rust

//! Various extensions traits for Chalk types.
use chalk_ir::{FloatTy, IntTy, Mutability, Scalar, UintTy};
use hir_def::{
builtin_type::{BuiltinFloat, BuiltinInt, BuiltinType, BuiltinUint},
generics::TypeOrConstParamData,
type_ref::Rawness,
FunctionId, GenericDefId, HasModule, ItemContainerId, Lookup, TraitId,
};
use syntax::SmolStr;
use crate::{
db::HirDatabase, from_assoc_type_id, from_chalk_trait_id, from_foreign_def_id,
from_placeholder_idx, to_chalk_trait_id, utils::generics, AdtId, AliasEq, AliasTy, Binders,
CallableDefId, CallableSig, FnPointer, ImplTraitId, Interner, Lifetime, ProjectionTy,
QuantifiedWhereClause, Substitution, TraitRef, Ty, TyBuilder, TyKind, WhereClause,
};
pub trait TyExt {
fn is_unit(&self) -> bool;
fn is_never(&self) -> bool;
fn is_unknown(&self) -> bool;
fn is_ty_var(&self) -> bool;
fn as_adt(&self) -> Option<(hir_def::AdtId, &Substitution)>;
fn as_builtin(&self) -> Option<BuiltinType>;
fn as_tuple(&self) -> Option<&Substitution>;
fn as_fn_def(&self, db: &dyn HirDatabase) -> Option<FunctionId>;
fn as_reference(&self) -> Option<(&Ty, Lifetime, Mutability)>;
fn as_reference_or_ptr(&self) -> Option<(&Ty, Rawness, Mutability)>;
fn as_generic_def(&self, db: &dyn HirDatabase) -> Option<GenericDefId>;
fn callable_def(&self, db: &dyn HirDatabase) -> Option<CallableDefId>;
fn callable_sig(&self, db: &dyn HirDatabase) -> Option<CallableSig>;
fn strip_references(&self) -> &Ty;
fn strip_reference(&self) -> &Ty;
/// If this is a `dyn Trait`, returns that trait.
fn dyn_trait(&self) -> Option<TraitId>;
fn impl_trait_bounds(&self, db: &dyn HirDatabase) -> Option<Vec<QuantifiedWhereClause>>;
fn associated_type_parent_trait(&self, db: &dyn HirDatabase) -> Option<TraitId>;
/// FIXME: Get rid of this, it's not a good abstraction
fn equals_ctor(&self, other: &Ty) -> bool;
}
impl TyExt for Ty {
fn is_unit(&self) -> bool {
matches!(self.kind(Interner), TyKind::Tuple(0, _))
}
fn is_never(&self) -> bool {
matches!(self.kind(Interner), TyKind::Never)
}
fn is_unknown(&self) -> bool {
matches!(self.kind(Interner), TyKind::Error)
}
fn is_ty_var(&self) -> bool {
matches!(self.kind(Interner), TyKind::InferenceVar(_, _))
}
fn as_adt(&self) -> Option<(hir_def::AdtId, &Substitution)> {
match self.kind(Interner) {
TyKind::Adt(AdtId(adt), parameters) => Some((*adt, parameters)),
_ => None,
}
}
fn as_builtin(&self) -> Option<BuiltinType> {
match self.kind(Interner) {
TyKind::Str => Some(BuiltinType::Str),
TyKind::Scalar(Scalar::Bool) => Some(BuiltinType::Bool),
TyKind::Scalar(Scalar::Char) => Some(BuiltinType::Char),
TyKind::Scalar(Scalar::Float(fty)) => Some(BuiltinType::Float(match fty {
FloatTy::F64 => BuiltinFloat::F64,
FloatTy::F32 => BuiltinFloat::F32,
})),
TyKind::Scalar(Scalar::Int(ity)) => Some(BuiltinType::Int(match ity {
IntTy::Isize => BuiltinInt::Isize,
IntTy::I8 => BuiltinInt::I8,
IntTy::I16 => BuiltinInt::I16,
IntTy::I32 => BuiltinInt::I32,
IntTy::I64 => BuiltinInt::I64,
IntTy::I128 => BuiltinInt::I128,
})),
TyKind::Scalar(Scalar::Uint(ity)) => Some(BuiltinType::Uint(match ity {
UintTy::Usize => BuiltinUint::Usize,
UintTy::U8 => BuiltinUint::U8,
UintTy::U16 => BuiltinUint::U16,
UintTy::U32 => BuiltinUint::U32,
UintTy::U64 => BuiltinUint::U64,
UintTy::U128 => BuiltinUint::U128,
})),
_ => None,
}
}
fn as_tuple(&self) -> Option<&Substitution> {
match self.kind(Interner) {
TyKind::Tuple(_, substs) => Some(substs),
_ => None,
}
}
fn as_fn_def(&self, db: &dyn HirDatabase) -> Option<FunctionId> {
match self.callable_def(db) {
Some(CallableDefId::FunctionId(func)) => Some(func),
Some(CallableDefId::StructId(_) | CallableDefId::EnumVariantId(_)) | None => None,
}
}
fn as_reference(&self) -> Option<(&Ty, Lifetime, Mutability)> {
match self.kind(Interner) {
TyKind::Ref(mutability, lifetime, ty) => Some((ty, lifetime.clone(), *mutability)),
_ => None,
}
}
fn as_reference_or_ptr(&self) -> Option<(&Ty, Rawness, Mutability)> {
match self.kind(Interner) {
TyKind::Ref(mutability, _, ty) => Some((ty, Rawness::Ref, *mutability)),
TyKind::Raw(mutability, ty) => Some((ty, Rawness::RawPtr, *mutability)),
_ => None,
}
}
fn as_generic_def(&self, db: &dyn HirDatabase) -> Option<GenericDefId> {
match *self.kind(Interner) {
TyKind::Adt(AdtId(adt), ..) => Some(adt.into()),
TyKind::FnDef(callable, ..) => {
Some(db.lookup_intern_callable_def(callable.into()).into())
}
TyKind::AssociatedType(type_alias, ..) => Some(from_assoc_type_id(type_alias).into()),
TyKind::Foreign(type_alias, ..) => Some(from_foreign_def_id(type_alias).into()),
_ => None,
}
}
fn callable_def(&self, db: &dyn HirDatabase) -> Option<CallableDefId> {
match self.kind(Interner) {
&TyKind::FnDef(def, ..) => Some(db.lookup_intern_callable_def(def.into())),
_ => None,
}
}
fn callable_sig(&self, db: &dyn HirDatabase) -> Option<CallableSig> {
match self.kind(Interner) {
TyKind::Function(fn_ptr) => Some(CallableSig::from_fn_ptr(fn_ptr)),
TyKind::FnDef(def, parameters) => {
let callable_def = db.lookup_intern_callable_def((*def).into());
let sig = db.callable_item_signature(callable_def);
Some(sig.substitute(Interner, parameters))
}
TyKind::Closure(.., substs) => {
let sig_param = substs.at(Interner, 0).assert_ty_ref(Interner);
sig_param.callable_sig(db)
}
_ => None,
}
}
fn dyn_trait(&self) -> Option<TraitId> {
let trait_ref = match self.kind(Interner) {
// The principal trait bound should be the first element of the bounds. This is an
// invariant ensured by `TyLoweringContext::lower_dyn_trait()`.
// FIXME: dyn types may not have principal trait and we don't want to return auto trait
// here.
TyKind::Dyn(dyn_ty) => dyn_ty.bounds.skip_binders().interned().get(0).and_then(|b| {
match b.skip_binders() {
WhereClause::Implemented(trait_ref) => Some(trait_ref),
_ => None,
}
}),
_ => None,
}?;
Some(from_chalk_trait_id(trait_ref.trait_id))
}
fn strip_references(&self) -> &Ty {
let mut t: &Ty = self;
while let TyKind::Ref(_mutability, _lifetime, ty) = t.kind(Interner) {
t = ty;
}
t
}
fn strip_reference(&self) -> &Ty {
self.as_reference().map_or(self, |(ty, _, _)| ty)
}
fn impl_trait_bounds(&self, db: &dyn HirDatabase) -> Option<Vec<QuantifiedWhereClause>> {
match self.kind(Interner) {
TyKind::OpaqueType(opaque_ty_id, subst) => {
match db.lookup_intern_impl_trait_id((*opaque_ty_id).into()) {
ImplTraitId::AsyncBlockTypeImplTrait(def, _expr) => {
let krate = def.module(db.upcast()).krate();
if let Some(future_trait) = db
.lang_item(krate, SmolStr::new_inline("future_trait"))
.and_then(|item| item.as_trait())
{
// This is only used by type walking.
// Parameters will be walked outside, and projection predicate is not used.
// So just provide the Future trait.
let impl_bound = Binders::empty(
Interner,
WhereClause::Implemented(TraitRef {
trait_id: to_chalk_trait_id(future_trait),
substitution: Substitution::empty(Interner),
}),
);
Some(vec![impl_bound])
} else {
None
}
}
ImplTraitId::ReturnTypeImplTrait(func, idx) => {
db.return_type_impl_traits(func).map(|it| {
let data = (*it)
.as_ref()
.map(|rpit| rpit.impl_traits[idx as usize].bounds.clone());
data.substitute(Interner, &subst).into_value_and_skipped_binders().0
})
}
}
}
TyKind::Alias(AliasTy::Opaque(opaque_ty)) => {
let predicates = match db.lookup_intern_impl_trait_id(opaque_ty.opaque_ty_id.into())
{
ImplTraitId::ReturnTypeImplTrait(func, idx) => {
db.return_type_impl_traits(func).map(|it| {
let data = (*it)
.as_ref()
.map(|rpit| rpit.impl_traits[idx as usize].bounds.clone());
data.substitute(Interner, &opaque_ty.substitution)
})
}
// It always has an parameter for Future::Output type.
ImplTraitId::AsyncBlockTypeImplTrait(..) => unreachable!(),
};
predicates.map(|it| it.into_value_and_skipped_binders().0)
}
TyKind::Placeholder(idx) => {
let id = from_placeholder_idx(db, *idx);
let generic_params = db.generic_params(id.parent);
let param_data = &generic_params.type_or_consts[id.local_id];
match param_data {
TypeOrConstParamData::TypeParamData(p) => match p.provenance {
hir_def::generics::TypeParamProvenance::ArgumentImplTrait => {
let substs = TyBuilder::placeholder_subst(db, id.parent);
let predicates = db
.generic_predicates(id.parent)
.iter()
.map(|pred| pred.clone().substitute(Interner, &substs))
.filter(|wc| match &wc.skip_binders() {
WhereClause::Implemented(tr) => {
&tr.self_type_parameter(Interner) == self
}
WhereClause::AliasEq(AliasEq {
alias: AliasTy::Projection(proj),
ty: _,
}) => &proj.self_type_parameter(db) == self,
_ => false,
})
.collect::<Vec<_>>();
Some(predicates)
}
_ => None,
},
_ => None,
}
}
_ => None,
}
}
fn associated_type_parent_trait(&self, db: &dyn HirDatabase) -> Option<TraitId> {
match self.kind(Interner) {
TyKind::AssociatedType(id, ..) => {
match from_assoc_type_id(*id).lookup(db.upcast()).container {
ItemContainerId::TraitId(trait_id) => Some(trait_id),
_ => None,
}
}
TyKind::Alias(AliasTy::Projection(projection_ty)) => {
match from_assoc_type_id(projection_ty.associated_ty_id)
.lookup(db.upcast())
.container
{
ItemContainerId::TraitId(trait_id) => Some(trait_id),
_ => None,
}
}
_ => None,
}
}
fn equals_ctor(&self, other: &Ty) -> bool {
match (self.kind(Interner), other.kind(Interner)) {
(TyKind::Adt(adt, ..), TyKind::Adt(adt2, ..)) => adt == adt2,
(TyKind::Slice(_), TyKind::Slice(_)) | (TyKind::Array(_, _), TyKind::Array(_, _)) => {
true
}
(TyKind::FnDef(def_id, ..), TyKind::FnDef(def_id2, ..)) => def_id == def_id2,
(TyKind::OpaqueType(ty_id, ..), TyKind::OpaqueType(ty_id2, ..)) => ty_id == ty_id2,
(TyKind::AssociatedType(ty_id, ..), TyKind::AssociatedType(ty_id2, ..)) => {
ty_id == ty_id2
}
(TyKind::Foreign(ty_id, ..), TyKind::Foreign(ty_id2, ..)) => ty_id == ty_id2,
(TyKind::Closure(id1, _), TyKind::Closure(id2, _)) => id1 == id2,
(TyKind::Ref(mutability, ..), TyKind::Ref(mutability2, ..))
| (TyKind::Raw(mutability, ..), TyKind::Raw(mutability2, ..)) => {
mutability == mutability2
}
(
TyKind::Function(FnPointer { num_binders, sig, .. }),
TyKind::Function(FnPointer { num_binders: num_binders2, sig: sig2, .. }),
) => num_binders == num_binders2 && sig == sig2,
(TyKind::Tuple(cardinality, _), TyKind::Tuple(cardinality2, _)) => {
cardinality == cardinality2
}
(TyKind::Str, TyKind::Str) | (TyKind::Never, TyKind::Never) => true,
(TyKind::Scalar(scalar), TyKind::Scalar(scalar2)) => scalar == scalar2,
_ => false,
}
}
}
pub trait ProjectionTyExt {
fn trait_ref(&self, db: &dyn HirDatabase) -> TraitRef;
fn trait_(&self, db: &dyn HirDatabase) -> TraitId;
fn self_type_parameter(&self, db: &dyn HirDatabase) -> Ty;
}
impl ProjectionTyExt for ProjectionTy {
fn trait_ref(&self, db: &dyn HirDatabase) -> TraitRef {
// FIXME: something like `Split` trait from chalk-solve might be nice.
let generics = generics(db.upcast(), from_assoc_type_id(self.associated_ty_id).into());
let substitution = Substitution::from_iter(
Interner,
self.substitution.iter(Interner).skip(generics.len_self()),
);
TraitRef { trait_id: to_chalk_trait_id(self.trait_(db)), substitution }
}
fn trait_(&self, db: &dyn HirDatabase) -> TraitId {
match from_assoc_type_id(self.associated_ty_id).lookup(db.upcast()).container {
ItemContainerId::TraitId(it) => it,
_ => panic!("projection ty without parent trait"),
}
}
fn self_type_parameter(&self, db: &dyn HirDatabase) -> Ty {
self.trait_ref(db).self_type_parameter(Interner)
}
}
pub trait TraitRefExt {
fn hir_trait_id(&self) -> TraitId;
}
impl TraitRefExt for TraitRef {
fn hir_trait_id(&self) -> TraitId {
from_chalk_trait_id(self.trait_id)
}
}