1779 lines
74 KiB
Rust
1779 lines
74 KiB
Rust
//! Methods for lowering the HIR to types. There are two main cases here:
|
|
//!
|
|
//! - Lowering a type reference like `&usize` or `Option<foo::bar::Baz>` to a
|
|
//! type: The entry point for this is `Ty::from_hir`.
|
|
//! - Building the type for an item: This happens through the `type_for_def` query.
|
|
//!
|
|
//! This usually involves resolving names, collecting generic arguments etc.
|
|
use std::{
|
|
cell::{Cell, RefCell},
|
|
iter,
|
|
sync::Arc,
|
|
};
|
|
|
|
use base_db::CrateId;
|
|
use chalk_ir::{
|
|
cast::Cast, fold::Shift, fold::TypeFoldable, interner::HasInterner, Mutability, Safety,
|
|
};
|
|
|
|
use hir_def::{
|
|
adt::StructKind,
|
|
body::{Expander, LowerCtx},
|
|
builtin_type::BuiltinType,
|
|
generics::{
|
|
TypeOrConstParamData, TypeParamProvenance, WherePredicate, WherePredicateTypeTarget,
|
|
},
|
|
intern::Interned,
|
|
lang_item::lang_attr,
|
|
path::{GenericArg, ModPath, Path, PathKind, PathSegment, PathSegments},
|
|
resolver::{HasResolver, Resolver, TypeNs},
|
|
type_ref::{
|
|
ConstScalarOrPath, TraitBoundModifier, TraitRef as HirTraitRef, TypeBound, TypeRef,
|
|
},
|
|
AdtId, AssocItemId, ConstId, ConstParamId, EnumId, EnumVariantId, FunctionId, GenericDefId,
|
|
HasModule, ImplId, ItemContainerId, LocalFieldId, Lookup, StaticId, StructId, TraitId,
|
|
TypeAliasId, TypeOrConstParamId, TypeParamId, UnionId, VariantId,
|
|
};
|
|
use hir_expand::{name::Name, ExpandResult};
|
|
use itertools::Either;
|
|
use la_arena::ArenaMap;
|
|
use rustc_hash::FxHashSet;
|
|
use smallvec::SmallVec;
|
|
use stdx::{impl_from, never};
|
|
use syntax::{ast, SmolStr};
|
|
|
|
use crate::{
|
|
all_super_traits,
|
|
consteval::{intern_const_scalar, path_to_const, unknown_const, unknown_const_as_generic},
|
|
db::HirDatabase,
|
|
make_binders,
|
|
mapping::ToChalk,
|
|
static_lifetime, to_assoc_type_id, to_chalk_trait_id, to_placeholder_idx,
|
|
utils::Generics,
|
|
utils::{all_super_trait_refs, associated_type_by_name_including_super_traits, generics},
|
|
AliasEq, AliasTy, Binders, BoundVar, CallableSig, Const, DebruijnIndex, DynTy, FnPointer,
|
|
FnSig, FnSubst, GenericArgData, ImplTraitId, Interner, ParamKind, PolyFnSig, ProjectionTy,
|
|
QuantifiedWhereClause, QuantifiedWhereClauses, ReturnTypeImplTrait, ReturnTypeImplTraits,
|
|
Substitution, TraitEnvironment, TraitRef, TraitRefExt, Ty, TyBuilder, TyKind, WhereClause,
|
|
};
|
|
|
|
#[derive(Debug)]
|
|
pub struct TyLoweringContext<'a> {
|
|
pub db: &'a dyn HirDatabase,
|
|
pub resolver: &'a Resolver,
|
|
in_binders: DebruijnIndex,
|
|
/// Note: Conceptually, it's thinkable that we could be in a location where
|
|
/// some type params should be represented as placeholders, and others
|
|
/// should be converted to variables. I think in practice, this isn't
|
|
/// possible currently, so this should be fine for now.
|
|
pub type_param_mode: ParamLoweringMode,
|
|
pub impl_trait_mode: ImplTraitLoweringMode,
|
|
impl_trait_counter: Cell<u16>,
|
|
/// When turning `impl Trait` into opaque types, we have to collect the
|
|
/// bounds at the same time to get the IDs correct (without becoming too
|
|
/// complicated). I don't like using interior mutability (as for the
|
|
/// counter), but I've tried and failed to make the lifetimes work for
|
|
/// passing around a `&mut TyLoweringContext`. The core problem is that
|
|
/// we're grouping the mutable data (the counter and this field) together
|
|
/// with the immutable context (the references to the DB and resolver).
|
|
/// Splitting this up would be a possible fix.
|
|
opaque_type_data: RefCell<Vec<ReturnTypeImplTrait>>,
|
|
expander: RefCell<Option<Expander>>,
|
|
/// Tracks types with explicit `?Sized` bounds.
|
|
pub(crate) unsized_types: RefCell<FxHashSet<Ty>>,
|
|
}
|
|
|
|
impl<'a> TyLoweringContext<'a> {
|
|
pub fn new(db: &'a dyn HirDatabase, resolver: &'a Resolver) -> Self {
|
|
let impl_trait_counter = Cell::new(0);
|
|
let impl_trait_mode = ImplTraitLoweringMode::Disallowed;
|
|
let type_param_mode = ParamLoweringMode::Placeholder;
|
|
let in_binders = DebruijnIndex::INNERMOST;
|
|
let opaque_type_data = RefCell::new(Vec::new());
|
|
Self {
|
|
db,
|
|
resolver,
|
|
in_binders,
|
|
impl_trait_mode,
|
|
impl_trait_counter,
|
|
type_param_mode,
|
|
opaque_type_data,
|
|
expander: RefCell::new(None),
|
|
unsized_types: RefCell::default(),
|
|
}
|
|
}
|
|
|
|
pub fn with_debruijn<T>(
|
|
&self,
|
|
debruijn: DebruijnIndex,
|
|
f: impl FnOnce(&TyLoweringContext<'_>) -> T,
|
|
) -> T {
|
|
let opaque_ty_data_vec = self.opaque_type_data.take();
|
|
let expander = self.expander.take();
|
|
let unsized_types = self.unsized_types.take();
|
|
let new_ctx = Self {
|
|
in_binders: debruijn,
|
|
impl_trait_counter: Cell::new(self.impl_trait_counter.get()),
|
|
opaque_type_data: RefCell::new(opaque_ty_data_vec),
|
|
expander: RefCell::new(expander),
|
|
unsized_types: RefCell::new(unsized_types),
|
|
..*self
|
|
};
|
|
let result = f(&new_ctx);
|
|
self.impl_trait_counter.set(new_ctx.impl_trait_counter.get());
|
|
self.opaque_type_data.replace(new_ctx.opaque_type_data.into_inner());
|
|
self.expander.replace(new_ctx.expander.into_inner());
|
|
self.unsized_types.replace(new_ctx.unsized_types.into_inner());
|
|
result
|
|
}
|
|
|
|
pub fn with_shifted_in<T>(
|
|
&self,
|
|
debruijn: DebruijnIndex,
|
|
f: impl FnOnce(&TyLoweringContext<'_>) -> T,
|
|
) -> T {
|
|
self.with_debruijn(self.in_binders.shifted_in_from(debruijn), f)
|
|
}
|
|
|
|
pub fn with_impl_trait_mode(self, impl_trait_mode: ImplTraitLoweringMode) -> Self {
|
|
Self { impl_trait_mode, ..self }
|
|
}
|
|
|
|
pub fn with_type_param_mode(self, type_param_mode: ParamLoweringMode) -> Self {
|
|
Self { type_param_mode, ..self }
|
|
}
|
|
}
|
|
|
|
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
|
|
pub enum ImplTraitLoweringMode {
|
|
/// `impl Trait` gets lowered into an opaque type that doesn't unify with
|
|
/// anything except itself. This is used in places where values flow 'out',
|
|
/// i.e. for arguments of the function we're currently checking, and return
|
|
/// types of functions we're calling.
|
|
Opaque,
|
|
/// `impl Trait` gets lowered into a type variable. Used for argument
|
|
/// position impl Trait when inside the respective function, since it allows
|
|
/// us to support that without Chalk.
|
|
Param,
|
|
/// `impl Trait` gets lowered into a variable that can unify with some
|
|
/// type. This is used in places where values flow 'in', i.e. for arguments
|
|
/// of functions we're calling, and the return type of the function we're
|
|
/// currently checking.
|
|
Variable,
|
|
/// `impl Trait` is disallowed and will be an error.
|
|
Disallowed,
|
|
}
|
|
|
|
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
|
|
pub enum ParamLoweringMode {
|
|
Placeholder,
|
|
Variable,
|
|
}
|
|
|
|
impl<'a> TyLoweringContext<'a> {
|
|
pub fn lower_ty(&self, type_ref: &TypeRef) -> Ty {
|
|
self.lower_ty_ext(type_ref).0
|
|
}
|
|
|
|
fn generics(&self) -> Generics {
|
|
generics(
|
|
self.db.upcast(),
|
|
self.resolver
|
|
.generic_def()
|
|
.expect("there should be generics if there's a generic param"),
|
|
)
|
|
}
|
|
|
|
pub fn lower_ty_ext(&self, type_ref: &TypeRef) -> (Ty, Option<TypeNs>) {
|
|
let mut res = None;
|
|
let ty = match type_ref {
|
|
TypeRef::Never => TyKind::Never.intern(Interner),
|
|
TypeRef::Tuple(inner) => {
|
|
let inner_tys = inner.iter().map(|tr| self.lower_ty(tr));
|
|
TyKind::Tuple(inner_tys.len(), Substitution::from_iter(Interner, inner_tys))
|
|
.intern(Interner)
|
|
}
|
|
TypeRef::Path(path) => {
|
|
let (ty, res_) = self.lower_path(path);
|
|
res = res_;
|
|
ty
|
|
}
|
|
TypeRef::RawPtr(inner, mutability) => {
|
|
let inner_ty = self.lower_ty(inner);
|
|
TyKind::Raw(lower_to_chalk_mutability(*mutability), inner_ty).intern(Interner)
|
|
}
|
|
TypeRef::Array(inner, len) => {
|
|
let inner_ty = self.lower_ty(inner);
|
|
let const_len = const_or_path_to_chalk(
|
|
self.db,
|
|
self.resolver,
|
|
TyBuilder::usize(),
|
|
len,
|
|
self.type_param_mode,
|
|
|| self.generics(),
|
|
self.in_binders,
|
|
);
|
|
|
|
TyKind::Array(inner_ty, const_len).intern(Interner)
|
|
}
|
|
TypeRef::Slice(inner) => {
|
|
let inner_ty = self.lower_ty(inner);
|
|
TyKind::Slice(inner_ty).intern(Interner)
|
|
}
|
|
TypeRef::Reference(inner, _, mutability) => {
|
|
let inner_ty = self.lower_ty(inner);
|
|
let lifetime = static_lifetime();
|
|
TyKind::Ref(lower_to_chalk_mutability(*mutability), lifetime, inner_ty)
|
|
.intern(Interner)
|
|
}
|
|
TypeRef::Placeholder => TyKind::Error.intern(Interner),
|
|
TypeRef::Fn(params, is_varargs) => {
|
|
let substs = self.with_shifted_in(DebruijnIndex::ONE, |ctx| {
|
|
Substitution::from_iter(Interner, params.iter().map(|(_, tr)| ctx.lower_ty(tr)))
|
|
});
|
|
TyKind::Function(FnPointer {
|
|
num_binders: 0, // FIXME lower `for<'a> fn()` correctly
|
|
sig: FnSig { abi: (), safety: Safety::Safe, variadic: *is_varargs },
|
|
substitution: FnSubst(substs),
|
|
})
|
|
.intern(Interner)
|
|
}
|
|
TypeRef::DynTrait(bounds) => {
|
|
let self_ty =
|
|
TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0)).intern(Interner);
|
|
let bounds = self.with_shifted_in(DebruijnIndex::ONE, |ctx| {
|
|
QuantifiedWhereClauses::from_iter(
|
|
Interner,
|
|
bounds.iter().flat_map(|b| ctx.lower_type_bound(b, self_ty.clone(), false)),
|
|
)
|
|
});
|
|
let bounds = crate::make_single_type_binders(bounds);
|
|
TyKind::Dyn(DynTy { bounds, lifetime: static_lifetime() }).intern(Interner)
|
|
}
|
|
TypeRef::ImplTrait(bounds) => {
|
|
match self.impl_trait_mode {
|
|
ImplTraitLoweringMode::Opaque => {
|
|
let idx = self.impl_trait_counter.get();
|
|
self.impl_trait_counter.set(idx + 1);
|
|
let func = match self.resolver.generic_def() {
|
|
Some(GenericDefId::FunctionId(f)) => f,
|
|
_ => panic!("opaque impl trait lowering in non-function"),
|
|
};
|
|
|
|
assert!(idx as usize == self.opaque_type_data.borrow().len());
|
|
// this dance is to make sure the data is in the right
|
|
// place even if we encounter more opaque types while
|
|
// lowering the bounds
|
|
self.opaque_type_data.borrow_mut().push(ReturnTypeImplTrait {
|
|
bounds: crate::make_single_type_binders(Vec::new()),
|
|
});
|
|
// We don't want to lower the bounds inside the binders
|
|
// we're currently in, because they don't end up inside
|
|
// those binders. E.g. when we have `impl Trait<impl
|
|
// OtherTrait<T>>`, the `impl OtherTrait<T>` can't refer
|
|
// to the self parameter from `impl Trait`, and the
|
|
// bounds aren't actually stored nested within each
|
|
// other, but separately. So if the `T` refers to a type
|
|
// parameter of the outer function, it's just one binder
|
|
// away instead of two.
|
|
let actual_opaque_type_data = self
|
|
.with_debruijn(DebruijnIndex::INNERMOST, |ctx| {
|
|
ctx.lower_impl_trait(bounds, func)
|
|
});
|
|
self.opaque_type_data.borrow_mut()[idx as usize] = actual_opaque_type_data;
|
|
|
|
let impl_trait_id = ImplTraitId::ReturnTypeImplTrait(func, idx);
|
|
let opaque_ty_id = self.db.intern_impl_trait_id(impl_trait_id).into();
|
|
let generics = generics(self.db.upcast(), func.into());
|
|
let parameters = generics.bound_vars_subst(self.db, self.in_binders);
|
|
TyKind::OpaqueType(opaque_ty_id, parameters).intern(Interner)
|
|
}
|
|
ImplTraitLoweringMode::Param => {
|
|
let idx = self.impl_trait_counter.get();
|
|
// FIXME we're probably doing something wrong here
|
|
self.impl_trait_counter.set(idx + count_impl_traits(type_ref) as u16);
|
|
if let Some(def) = self.resolver.generic_def() {
|
|
let generics = generics(self.db.upcast(), def);
|
|
let param = generics
|
|
.iter()
|
|
.filter(|(_, data)| {
|
|
matches!(
|
|
data,
|
|
TypeOrConstParamData::TypeParamData(data)
|
|
if data.provenance == TypeParamProvenance::ArgumentImplTrait
|
|
)
|
|
})
|
|
.nth(idx as usize)
|
|
.map_or(TyKind::Error, |(id, _)| {
|
|
TyKind::Placeholder(to_placeholder_idx(self.db, id))
|
|
});
|
|
param.intern(Interner)
|
|
} else {
|
|
TyKind::Error.intern(Interner)
|
|
}
|
|
}
|
|
ImplTraitLoweringMode::Variable => {
|
|
let idx = self.impl_trait_counter.get();
|
|
// FIXME we're probably doing something wrong here
|
|
self.impl_trait_counter.set(idx + count_impl_traits(type_ref) as u16);
|
|
let (
|
|
parent_params,
|
|
self_params,
|
|
list_params,
|
|
const_params,
|
|
_impl_trait_params,
|
|
) = if let Some(def) = self.resolver.generic_def() {
|
|
let generics = generics(self.db.upcast(), def);
|
|
generics.provenance_split()
|
|
} else {
|
|
(0, 0, 0, 0, 0)
|
|
};
|
|
TyKind::BoundVar(BoundVar::new(
|
|
self.in_binders,
|
|
idx as usize + parent_params + self_params + list_params + const_params,
|
|
))
|
|
.intern(Interner)
|
|
}
|
|
ImplTraitLoweringMode::Disallowed => {
|
|
// FIXME: report error
|
|
TyKind::Error.intern(Interner)
|
|
}
|
|
}
|
|
}
|
|
TypeRef::Macro(macro_call) => {
|
|
let (expander, recursion_start) = {
|
|
let mut expander = self.expander.borrow_mut();
|
|
if expander.is_some() {
|
|
(Some(expander), false)
|
|
} else {
|
|
*expander = Some(Expander::new(
|
|
self.db.upcast(),
|
|
macro_call.file_id,
|
|
self.resolver.module(),
|
|
));
|
|
(Some(expander), true)
|
|
}
|
|
};
|
|
let ty = if let Some(mut expander) = expander {
|
|
let expander_mut = expander.as_mut().unwrap();
|
|
let macro_call = macro_call.to_node(self.db.upcast());
|
|
match expander_mut.enter_expand::<ast::Type>(self.db.upcast(), macro_call) {
|
|
Ok(ExpandResult { value: Some((mark, expanded)), .. }) => {
|
|
let ctx =
|
|
LowerCtx::new(self.db.upcast(), expander_mut.current_file_id());
|
|
let type_ref = TypeRef::from_ast(&ctx, expanded);
|
|
|
|
drop(expander);
|
|
let ty = self.lower_ty(&type_ref);
|
|
|
|
self.expander
|
|
.borrow_mut()
|
|
.as_mut()
|
|
.unwrap()
|
|
.exit(self.db.upcast(), mark);
|
|
Some(ty)
|
|
}
|
|
_ => None,
|
|
}
|
|
} else {
|
|
None
|
|
};
|
|
if recursion_start {
|
|
*self.expander.borrow_mut() = None;
|
|
}
|
|
ty.unwrap_or_else(|| TyKind::Error.intern(Interner))
|
|
}
|
|
TypeRef::Error => TyKind::Error.intern(Interner),
|
|
};
|
|
(ty, res)
|
|
}
|
|
|
|
/// This is only for `generic_predicates_for_param`, where we can't just
|
|
/// lower the self types of the predicates since that could lead to cycles.
|
|
/// So we just check here if the `type_ref` resolves to a generic param, and which.
|
|
fn lower_ty_only_param(&self, type_ref: &TypeRef) -> Option<TypeOrConstParamId> {
|
|
let path = match type_ref {
|
|
TypeRef::Path(path) => path,
|
|
_ => return None,
|
|
};
|
|
if path.type_anchor().is_some() {
|
|
return None;
|
|
}
|
|
if path.segments().len() > 1 {
|
|
return None;
|
|
}
|
|
let resolution =
|
|
match self.resolver.resolve_path_in_type_ns(self.db.upcast(), path.mod_path()) {
|
|
Some((it, None)) => it,
|
|
_ => return None,
|
|
};
|
|
match resolution {
|
|
TypeNs::GenericParam(param_id) => Some(param_id.into()),
|
|
_ => None,
|
|
}
|
|
}
|
|
|
|
pub(crate) fn lower_ty_relative_path(
|
|
&self,
|
|
ty: Ty,
|
|
// We need the original resolution to lower `Self::AssocTy` correctly
|
|
res: Option<TypeNs>,
|
|
remaining_segments: PathSegments<'_>,
|
|
) -> (Ty, Option<TypeNs>) {
|
|
match remaining_segments.len() {
|
|
0 => (ty, res),
|
|
1 => {
|
|
// resolve unselected assoc types
|
|
let segment = remaining_segments.first().unwrap();
|
|
(self.select_associated_type(res, segment), None)
|
|
}
|
|
_ => {
|
|
// FIXME report error (ambiguous associated type)
|
|
(TyKind::Error.intern(Interner), None)
|
|
}
|
|
}
|
|
}
|
|
|
|
pub(crate) fn lower_partly_resolved_path(
|
|
&self,
|
|
resolution: TypeNs,
|
|
resolved_segment: PathSegment<'_>,
|
|
remaining_segments: PathSegments<'_>,
|
|
infer_args: bool,
|
|
) -> (Ty, Option<TypeNs>) {
|
|
let ty = match resolution {
|
|
TypeNs::TraitId(trait_) => {
|
|
let ty = match remaining_segments.len() {
|
|
1 => {
|
|
let trait_ref =
|
|
self.lower_trait_ref_from_resolved_path(trait_, resolved_segment, None);
|
|
let segment = remaining_segments.first().unwrap();
|
|
let found = self
|
|
.db
|
|
.trait_data(trait_ref.hir_trait_id())
|
|
.associated_type_by_name(segment.name);
|
|
match found {
|
|
Some(associated_ty) => {
|
|
// FIXME handle type parameters on the segment
|
|
TyKind::Alias(AliasTy::Projection(ProjectionTy {
|
|
associated_ty_id: to_assoc_type_id(associated_ty),
|
|
substitution: trait_ref.substitution,
|
|
}))
|
|
.intern(Interner)
|
|
}
|
|
None => {
|
|
// FIXME: report error (associated type not found)
|
|
TyKind::Error.intern(Interner)
|
|
}
|
|
}
|
|
}
|
|
0 => {
|
|
let self_ty = Some(
|
|
TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0))
|
|
.intern(Interner),
|
|
);
|
|
let trait_ref = self.with_shifted_in(DebruijnIndex::ONE, |ctx| {
|
|
ctx.lower_trait_ref_from_resolved_path(
|
|
trait_,
|
|
resolved_segment,
|
|
self_ty,
|
|
)
|
|
});
|
|
let dyn_ty = DynTy {
|
|
bounds: crate::make_single_type_binders(
|
|
QuantifiedWhereClauses::from_iter(
|
|
Interner,
|
|
Some(crate::wrap_empty_binders(WhereClause::Implemented(
|
|
trait_ref,
|
|
))),
|
|
),
|
|
),
|
|
lifetime: static_lifetime(),
|
|
};
|
|
TyKind::Dyn(dyn_ty).intern(Interner)
|
|
}
|
|
_ => {
|
|
// FIXME report error (ambiguous associated type)
|
|
TyKind::Error.intern(Interner)
|
|
}
|
|
};
|
|
return (ty, None);
|
|
}
|
|
TypeNs::GenericParam(param_id) => {
|
|
let generics = generics(
|
|
self.db.upcast(),
|
|
self.resolver.generic_def().expect("generics in scope"),
|
|
);
|
|
match self.type_param_mode {
|
|
ParamLoweringMode::Placeholder => {
|
|
TyKind::Placeholder(to_placeholder_idx(self.db, param_id.into()))
|
|
}
|
|
ParamLoweringMode::Variable => {
|
|
let idx = generics.param_idx(param_id.into()).expect("matching generics");
|
|
TyKind::BoundVar(BoundVar::new(self.in_binders, idx))
|
|
}
|
|
}
|
|
.intern(Interner)
|
|
}
|
|
TypeNs::SelfType(impl_id) => {
|
|
let generics = generics(self.db.upcast(), impl_id.into());
|
|
let substs = match self.type_param_mode {
|
|
ParamLoweringMode::Placeholder => generics.placeholder_subst(self.db),
|
|
ParamLoweringMode::Variable => {
|
|
generics.bound_vars_subst(self.db, self.in_binders)
|
|
}
|
|
};
|
|
self.db.impl_self_ty(impl_id).substitute(Interner, &substs)
|
|
}
|
|
TypeNs::AdtSelfType(adt) => {
|
|
let generics = generics(self.db.upcast(), adt.into());
|
|
let substs = match self.type_param_mode {
|
|
ParamLoweringMode::Placeholder => generics.placeholder_subst(self.db),
|
|
ParamLoweringMode::Variable => {
|
|
generics.bound_vars_subst(self.db, self.in_binders)
|
|
}
|
|
};
|
|
self.db.ty(adt.into()).substitute(Interner, &substs)
|
|
}
|
|
|
|
TypeNs::AdtId(it) => self.lower_path_inner(resolved_segment, it.into(), infer_args),
|
|
TypeNs::BuiltinType(it) => {
|
|
self.lower_path_inner(resolved_segment, it.into(), infer_args)
|
|
}
|
|
TypeNs::TypeAliasId(it) => {
|
|
self.lower_path_inner(resolved_segment, it.into(), infer_args)
|
|
}
|
|
// FIXME: report error
|
|
TypeNs::EnumVariantId(_) => return (TyKind::Error.intern(Interner), None),
|
|
};
|
|
self.lower_ty_relative_path(ty, Some(resolution), remaining_segments)
|
|
}
|
|
|
|
pub(crate) fn lower_path(&self, path: &Path) -> (Ty, Option<TypeNs>) {
|
|
// Resolve the path (in type namespace)
|
|
if let Some(type_ref) = path.type_anchor() {
|
|
let (ty, res) = self.lower_ty_ext(type_ref);
|
|
return self.lower_ty_relative_path(ty, res, path.segments());
|
|
}
|
|
let (resolution, remaining_index) =
|
|
match self.resolver.resolve_path_in_type_ns(self.db.upcast(), path.mod_path()) {
|
|
Some(it) => it,
|
|
None => return (TyKind::Error.intern(Interner), None),
|
|
};
|
|
let (resolved_segment, remaining_segments) = match remaining_index {
|
|
None => (
|
|
path.segments().last().expect("resolved path has at least one element"),
|
|
PathSegments::EMPTY,
|
|
),
|
|
Some(i) => (path.segments().get(i - 1).unwrap(), path.segments().skip(i)),
|
|
};
|
|
self.lower_partly_resolved_path(resolution, resolved_segment, remaining_segments, false)
|
|
}
|
|
|
|
fn select_associated_type(&self, res: Option<TypeNs>, segment: PathSegment<'_>) -> Ty {
|
|
let (def, res) = match (self.resolver.generic_def(), res) {
|
|
(Some(def), Some(res)) => (def, res),
|
|
_ => return TyKind::Error.intern(Interner),
|
|
};
|
|
let ty = named_associated_type_shorthand_candidates(
|
|
self.db,
|
|
def,
|
|
res,
|
|
Some(segment.name.clone()),
|
|
move |name, t, associated_ty| {
|
|
if name == segment.name {
|
|
let substs = match self.type_param_mode {
|
|
ParamLoweringMode::Placeholder => {
|
|
// if we're lowering to placeholders, we have to put
|
|
// them in now
|
|
let generics = generics(
|
|
self.db.upcast(),
|
|
self.resolver
|
|
.generic_def()
|
|
.expect("there should be generics if there's a generic param"),
|
|
);
|
|
let s = generics.placeholder_subst(self.db);
|
|
s.apply(t.substitution.clone(), Interner)
|
|
}
|
|
ParamLoweringMode::Variable => t.substitution.clone(),
|
|
};
|
|
// We need to shift in the bound vars, since
|
|
// associated_type_shorthand_candidates does not do that
|
|
let substs = substs.shifted_in_from(Interner, self.in_binders);
|
|
// FIXME handle type parameters on the segment
|
|
Some(
|
|
TyKind::Alias(AliasTy::Projection(ProjectionTy {
|
|
associated_ty_id: to_assoc_type_id(associated_ty),
|
|
substitution: substs,
|
|
}))
|
|
.intern(Interner),
|
|
)
|
|
} else {
|
|
None
|
|
}
|
|
},
|
|
);
|
|
|
|
ty.unwrap_or_else(|| TyKind::Error.intern(Interner))
|
|
}
|
|
|
|
fn lower_path_inner(
|
|
&self,
|
|
segment: PathSegment<'_>,
|
|
typeable: TyDefId,
|
|
infer_args: bool,
|
|
) -> Ty {
|
|
let generic_def = match typeable {
|
|
TyDefId::BuiltinType(_) => None,
|
|
TyDefId::AdtId(it) => Some(it.into()),
|
|
TyDefId::TypeAliasId(it) => Some(it.into()),
|
|
};
|
|
let substs = self.substs_from_path_segment(segment, generic_def, infer_args, None);
|
|
self.db.ty(typeable).substitute(Interner, &substs)
|
|
}
|
|
|
|
/// Collect generic arguments from a path into a `Substs`. See also
|
|
/// `create_substs_for_ast_path` and `def_to_ty` in rustc.
|
|
pub(super) fn substs_from_path(
|
|
&self,
|
|
path: &Path,
|
|
// Note that we don't call `db.value_type(resolved)` here,
|
|
// `ValueTyDefId` is just a convenient way to pass generics and
|
|
// special-case enum variants
|
|
resolved: ValueTyDefId,
|
|
infer_args: bool,
|
|
) -> Substitution {
|
|
let last = path.segments().last().expect("path should have at least one segment");
|
|
let (segment, generic_def) = match resolved {
|
|
ValueTyDefId::FunctionId(it) => (last, Some(it.into())),
|
|
ValueTyDefId::StructId(it) => (last, Some(it.into())),
|
|
ValueTyDefId::UnionId(it) => (last, Some(it.into())),
|
|
ValueTyDefId::ConstId(it) => (last, Some(it.into())),
|
|
ValueTyDefId::StaticId(_) => (last, None),
|
|
ValueTyDefId::EnumVariantId(var) => {
|
|
// the generic args for an enum variant may be either specified
|
|
// on the segment referring to the enum, or on the segment
|
|
// referring to the variant. So `Option::<T>::None` and
|
|
// `Option::None::<T>` are both allowed (though the former is
|
|
// preferred). See also `def_ids_for_path_segments` in rustc.
|
|
let len = path.segments().len();
|
|
let penultimate = len.checked_sub(2).and_then(|idx| path.segments().get(idx));
|
|
let segment = match penultimate {
|
|
Some(segment) if segment.args_and_bindings.is_some() => segment,
|
|
_ => last,
|
|
};
|
|
(segment, Some(var.parent.into()))
|
|
}
|
|
};
|
|
self.substs_from_path_segment(segment, generic_def, infer_args, None)
|
|
}
|
|
|
|
fn substs_from_path_segment(
|
|
&self,
|
|
segment: PathSegment<'_>,
|
|
def_generic: Option<GenericDefId>,
|
|
infer_args: bool,
|
|
explicit_self_ty: Option<Ty>,
|
|
) -> Substitution {
|
|
let mut substs = Vec::new();
|
|
let def_generics = if let Some(def) = def_generic {
|
|
generics(self.db.upcast(), def)
|
|
} else {
|
|
return Substitution::empty(Interner);
|
|
};
|
|
let (parent_params, self_params, type_params, const_params, impl_trait_params) =
|
|
def_generics.provenance_split();
|
|
let total_len =
|
|
parent_params + self_params + type_params + const_params + impl_trait_params;
|
|
|
|
let ty_error = GenericArgData::Ty(TyKind::Error.intern(Interner)).intern(Interner);
|
|
|
|
let mut def_generic_iter = def_generics.iter_id();
|
|
|
|
for _ in 0..parent_params {
|
|
if let Some(eid) = def_generic_iter.next() {
|
|
match eid {
|
|
Either::Left(_) => substs.push(ty_error.clone()),
|
|
Either::Right(x) => {
|
|
substs.push(unknown_const_as_generic(self.db.const_param_ty(x)))
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
let fill_self_params = || {
|
|
for x in explicit_self_ty
|
|
.into_iter()
|
|
.map(|x| GenericArgData::Ty(x).intern(Interner))
|
|
.chain(iter::repeat(ty_error.clone()))
|
|
.take(self_params)
|
|
{
|
|
if let Some(id) = def_generic_iter.next() {
|
|
assert!(id.is_left());
|
|
substs.push(x);
|
|
}
|
|
}
|
|
};
|
|
let mut had_explicit_args = false;
|
|
|
|
if let Some(generic_args) = &segment.args_and_bindings {
|
|
if !generic_args.has_self_type {
|
|
fill_self_params();
|
|
}
|
|
let expected_num = if generic_args.has_self_type {
|
|
self_params + type_params + const_params
|
|
} else {
|
|
type_params + const_params
|
|
};
|
|
let skip = if generic_args.has_self_type && self_params == 0 { 1 } else { 0 };
|
|
// if args are provided, it should be all of them, but we can't rely on that
|
|
for arg in generic_args
|
|
.args
|
|
.iter()
|
|
.filter(|arg| !matches!(arg, GenericArg::Lifetime(_)))
|
|
.skip(skip)
|
|
.take(expected_num)
|
|
{
|
|
if let Some(id) = def_generic_iter.next() {
|
|
if let Some(x) = generic_arg_to_chalk(
|
|
self.db,
|
|
id,
|
|
arg,
|
|
&mut (),
|
|
|_, type_ref| self.lower_ty(type_ref),
|
|
|_, c, ty| {
|
|
const_or_path_to_chalk(
|
|
self.db,
|
|
&self.resolver,
|
|
ty,
|
|
c,
|
|
self.type_param_mode,
|
|
|| self.generics(),
|
|
self.in_binders,
|
|
)
|
|
},
|
|
) {
|
|
had_explicit_args = true;
|
|
substs.push(x);
|
|
} else {
|
|
// we just filtered them out
|
|
never!("Unexpected lifetime argument");
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
fill_self_params();
|
|
}
|
|
|
|
// handle defaults. In expression or pattern path segments without
|
|
// explicitly specified type arguments, missing type arguments are inferred
|
|
// (i.e. defaults aren't used).
|
|
if !infer_args || had_explicit_args {
|
|
if let Some(def_generic) = def_generic {
|
|
let defaults = self.db.generic_defaults(def_generic);
|
|
assert_eq!(total_len, defaults.len());
|
|
|
|
for default_ty in defaults.iter().skip(substs.len()) {
|
|
// each default can depend on the previous parameters
|
|
let substs_so_far = Substitution::from_iter(Interner, substs.clone());
|
|
if let Some(_id) = def_generic_iter.next() {
|
|
substs.push(default_ty.clone().substitute(Interner, &substs_so_far));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// add placeholders for args that were not provided
|
|
// FIXME: emit diagnostics in contexts where this is not allowed
|
|
for eid in def_generic_iter {
|
|
match eid {
|
|
Either::Left(_) => substs.push(ty_error.clone()),
|
|
Either::Right(x) => {
|
|
substs.push(unknown_const_as_generic(self.db.const_param_ty(x)))
|
|
}
|
|
}
|
|
}
|
|
// If this assert fails, it means you pushed into subst but didn't call .next() of def_generic_iter
|
|
assert_eq!(substs.len(), total_len);
|
|
|
|
Substitution::from_iter(Interner, substs)
|
|
}
|
|
|
|
fn lower_trait_ref_from_path(
|
|
&self,
|
|
path: &Path,
|
|
explicit_self_ty: Option<Ty>,
|
|
) -> Option<TraitRef> {
|
|
let resolved =
|
|
match self.resolver.resolve_path_in_type_ns_fully(self.db.upcast(), path.mod_path())? {
|
|
TypeNs::TraitId(tr) => tr,
|
|
_ => return None,
|
|
};
|
|
let segment = path.segments().last().expect("path should have at least one segment");
|
|
Some(self.lower_trait_ref_from_resolved_path(resolved, segment, explicit_self_ty))
|
|
}
|
|
|
|
pub(crate) fn lower_trait_ref_from_resolved_path(
|
|
&self,
|
|
resolved: TraitId,
|
|
segment: PathSegment<'_>,
|
|
explicit_self_ty: Option<Ty>,
|
|
) -> TraitRef {
|
|
let substs = self.trait_ref_substs_from_path(segment, resolved, explicit_self_ty);
|
|
TraitRef { trait_id: to_chalk_trait_id(resolved), substitution: substs }
|
|
}
|
|
|
|
fn lower_trait_ref(
|
|
&self,
|
|
trait_ref: &HirTraitRef,
|
|
explicit_self_ty: Option<Ty>,
|
|
) -> Option<TraitRef> {
|
|
self.lower_trait_ref_from_path(&trait_ref.path, explicit_self_ty)
|
|
}
|
|
|
|
fn trait_ref_substs_from_path(
|
|
&self,
|
|
segment: PathSegment<'_>,
|
|
resolved: TraitId,
|
|
explicit_self_ty: Option<Ty>,
|
|
) -> Substitution {
|
|
self.substs_from_path_segment(segment, Some(resolved.into()), false, explicit_self_ty)
|
|
}
|
|
|
|
pub(crate) fn lower_where_predicate(
|
|
&'a self,
|
|
where_predicate: &'a WherePredicate,
|
|
ignore_bindings: bool,
|
|
) -> impl Iterator<Item = QuantifiedWhereClause> + 'a {
|
|
match where_predicate {
|
|
WherePredicate::ForLifetime { target, bound, .. }
|
|
| WherePredicate::TypeBound { target, bound } => {
|
|
let self_ty = match target {
|
|
WherePredicateTypeTarget::TypeRef(type_ref) => self.lower_ty(type_ref),
|
|
WherePredicateTypeTarget::TypeOrConstParam(param_id) => {
|
|
let generic_def = self.resolver.generic_def().expect("generics in scope");
|
|
let generics = generics(self.db.upcast(), generic_def);
|
|
let param_id = hir_def::TypeOrConstParamId {
|
|
parent: generic_def,
|
|
local_id: *param_id,
|
|
};
|
|
let placeholder = to_placeholder_idx(self.db, param_id);
|
|
match self.type_param_mode {
|
|
ParamLoweringMode::Placeholder => TyKind::Placeholder(placeholder),
|
|
ParamLoweringMode::Variable => {
|
|
let idx = generics.param_idx(param_id).expect("matching generics");
|
|
TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, idx))
|
|
}
|
|
}
|
|
.intern(Interner)
|
|
}
|
|
};
|
|
self.lower_type_bound(bound, self_ty, ignore_bindings)
|
|
.collect::<Vec<_>>()
|
|
.into_iter()
|
|
}
|
|
WherePredicate::Lifetime { .. } => vec![].into_iter(),
|
|
}
|
|
}
|
|
|
|
pub(crate) fn lower_type_bound(
|
|
&'a self,
|
|
bound: &'a TypeBound,
|
|
self_ty: Ty,
|
|
ignore_bindings: bool,
|
|
) -> impl Iterator<Item = QuantifiedWhereClause> + 'a {
|
|
let mut bindings = None;
|
|
let trait_ref = match bound {
|
|
TypeBound::Path(path, TraitBoundModifier::None) => {
|
|
bindings = self.lower_trait_ref_from_path(path, Some(self_ty));
|
|
bindings
|
|
.clone()
|
|
.filter(|tr| {
|
|
// ignore `T: Drop` or `T: Destruct` bounds.
|
|
// - `T: ~const Drop` has a special meaning in Rust 1.61 that we don't implement.
|
|
// (So ideally, we'd only ignore `~const Drop` here)
|
|
// - `Destruct` impls are built-in in 1.62 (current nightlies as of 08-04-2022), so until
|
|
// the builtin impls are supported by Chalk, we ignore them here.
|
|
if let Some(lang) = lang_attr(self.db.upcast(), tr.hir_trait_id()) {
|
|
if lang == "drop" || lang == "destruct" {
|
|
return false;
|
|
}
|
|
}
|
|
true
|
|
})
|
|
.map(WhereClause::Implemented)
|
|
.map(crate::wrap_empty_binders)
|
|
}
|
|
TypeBound::Path(path, TraitBoundModifier::Maybe) => {
|
|
let sized_trait = self
|
|
.db
|
|
.lang_item(self.resolver.krate(), SmolStr::new_inline("sized"))
|
|
.and_then(|lang_item| lang_item.as_trait());
|
|
// Don't lower associated type bindings as the only possible relaxed trait bound
|
|
// `?Sized` has no of them.
|
|
// If we got another trait here ignore the bound completely.
|
|
let trait_id = self
|
|
.lower_trait_ref_from_path(path, Some(self_ty.clone()))
|
|
.map(|trait_ref| trait_ref.hir_trait_id());
|
|
if trait_id == sized_trait {
|
|
self.unsized_types.borrow_mut().insert(self_ty);
|
|
}
|
|
None
|
|
}
|
|
TypeBound::ForLifetime(_, path) => {
|
|
// FIXME Don't silently drop the hrtb lifetimes here
|
|
bindings = self.lower_trait_ref_from_path(path, Some(self_ty));
|
|
bindings.clone().map(WhereClause::Implemented).map(crate::wrap_empty_binders)
|
|
}
|
|
TypeBound::Lifetime(_) => None,
|
|
TypeBound::Error => None,
|
|
};
|
|
trait_ref.into_iter().chain(
|
|
bindings
|
|
.into_iter()
|
|
.filter(move |_| !ignore_bindings)
|
|
.flat_map(move |tr| self.assoc_type_bindings_from_type_bound(bound, tr)),
|
|
)
|
|
}
|
|
|
|
fn assoc_type_bindings_from_type_bound(
|
|
&'a self,
|
|
bound: &'a TypeBound,
|
|
trait_ref: TraitRef,
|
|
) -> impl Iterator<Item = QuantifiedWhereClause> + 'a {
|
|
let last_segment = match bound {
|
|
TypeBound::Path(path, TraitBoundModifier::None) | TypeBound::ForLifetime(_, path) => {
|
|
path.segments().last()
|
|
}
|
|
TypeBound::Path(_, TraitBoundModifier::Maybe)
|
|
| TypeBound::Error
|
|
| TypeBound::Lifetime(_) => None,
|
|
};
|
|
last_segment
|
|
.into_iter()
|
|
.filter_map(|segment| segment.args_and_bindings)
|
|
.flat_map(|args_and_bindings| &args_and_bindings.bindings)
|
|
.flat_map(move |binding| {
|
|
let found = associated_type_by_name_including_super_traits(
|
|
self.db,
|
|
trait_ref.clone(),
|
|
&binding.name,
|
|
);
|
|
let (super_trait_ref, associated_ty) = match found {
|
|
None => return SmallVec::new(),
|
|
Some(t) => t,
|
|
};
|
|
let projection_ty = ProjectionTy {
|
|
associated_ty_id: to_assoc_type_id(associated_ty),
|
|
substitution: super_trait_ref.substitution,
|
|
};
|
|
let mut preds: SmallVec<[_; 1]> = SmallVec::with_capacity(
|
|
binding.type_ref.as_ref().map_or(0, |_| 1) + binding.bounds.len(),
|
|
);
|
|
if let Some(type_ref) = &binding.type_ref {
|
|
let ty = self.lower_ty(type_ref);
|
|
let alias_eq =
|
|
AliasEq { alias: AliasTy::Projection(projection_ty.clone()), ty };
|
|
preds.push(crate::wrap_empty_binders(WhereClause::AliasEq(alias_eq)));
|
|
}
|
|
for bound in &binding.bounds {
|
|
preds.extend(self.lower_type_bound(
|
|
bound,
|
|
TyKind::Alias(AliasTy::Projection(projection_ty.clone())).intern(Interner),
|
|
false,
|
|
));
|
|
}
|
|
preds
|
|
})
|
|
}
|
|
|
|
fn lower_impl_trait(
|
|
&self,
|
|
bounds: &[Interned<TypeBound>],
|
|
func: FunctionId,
|
|
) -> ReturnTypeImplTrait {
|
|
cov_mark::hit!(lower_rpit);
|
|
let self_ty = TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0)).intern(Interner);
|
|
let predicates = self.with_shifted_in(DebruijnIndex::ONE, |ctx| {
|
|
let mut predicates: Vec<_> = bounds
|
|
.iter()
|
|
.flat_map(|b| ctx.lower_type_bound(b, self_ty.clone(), false))
|
|
.collect();
|
|
|
|
if !ctx.unsized_types.borrow().contains(&self_ty) {
|
|
let krate = func.lookup(ctx.db.upcast()).module(ctx.db.upcast()).krate();
|
|
let sized_trait = ctx
|
|
.db
|
|
.lang_item(krate, SmolStr::new_inline("sized"))
|
|
.and_then(|lang_item| lang_item.as_trait().map(to_chalk_trait_id));
|
|
let sized_clause = sized_trait.map(|trait_id| {
|
|
let clause = WhereClause::Implemented(TraitRef {
|
|
trait_id,
|
|
substitution: Substitution::from1(Interner, self_ty.clone()),
|
|
});
|
|
crate::wrap_empty_binders(clause)
|
|
});
|
|
predicates.extend(sized_clause.into_iter());
|
|
predicates.shrink_to_fit();
|
|
}
|
|
predicates
|
|
});
|
|
ReturnTypeImplTrait { bounds: crate::make_single_type_binders(predicates) }
|
|
}
|
|
}
|
|
|
|
fn count_impl_traits(type_ref: &TypeRef) -> usize {
|
|
let mut count = 0;
|
|
type_ref.walk(&mut |type_ref| {
|
|
if matches!(type_ref, TypeRef::ImplTrait(_)) {
|
|
count += 1;
|
|
}
|
|
});
|
|
count
|
|
}
|
|
|
|
/// Build the signature of a callable item (function, struct or enum variant).
|
|
pub(crate) fn callable_item_sig(db: &dyn HirDatabase, def: CallableDefId) -> PolyFnSig {
|
|
match def {
|
|
CallableDefId::FunctionId(f) => fn_sig_for_fn(db, f),
|
|
CallableDefId::StructId(s) => fn_sig_for_struct_constructor(db, s),
|
|
CallableDefId::EnumVariantId(e) => fn_sig_for_enum_variant_constructor(db, e),
|
|
}
|
|
}
|
|
|
|
pub fn associated_type_shorthand_candidates<R>(
|
|
db: &dyn HirDatabase,
|
|
def: GenericDefId,
|
|
res: TypeNs,
|
|
cb: impl FnMut(&Name, &TraitRef, TypeAliasId) -> Option<R>,
|
|
) -> Option<R> {
|
|
named_associated_type_shorthand_candidates(db, def, res, None, cb)
|
|
}
|
|
|
|
fn named_associated_type_shorthand_candidates<R>(
|
|
db: &dyn HirDatabase,
|
|
// If the type parameter is defined in an impl and we're in a method, there
|
|
// might be additional where clauses to consider
|
|
def: GenericDefId,
|
|
res: TypeNs,
|
|
assoc_name: Option<Name>,
|
|
mut cb: impl FnMut(&Name, &TraitRef, TypeAliasId) -> Option<R>,
|
|
) -> Option<R> {
|
|
let mut search = |t| {
|
|
for t in all_super_trait_refs(db, t) {
|
|
let data = db.trait_data(t.hir_trait_id());
|
|
|
|
for (name, assoc_id) in &data.items {
|
|
if let AssocItemId::TypeAliasId(alias) = assoc_id {
|
|
if let Some(result) = cb(name, &t, *alias) {
|
|
return Some(result);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
None
|
|
};
|
|
|
|
match res {
|
|
TypeNs::SelfType(impl_id) => search(
|
|
// we're _in_ the impl -- the binders get added back later. Correct,
|
|
// but it would be nice to make this more explicit
|
|
db.impl_trait(impl_id)?.into_value_and_skipped_binders().0,
|
|
),
|
|
TypeNs::GenericParam(param_id) => {
|
|
let predicates = db.generic_predicates_for_param(def, param_id.into(), assoc_name);
|
|
let res = predicates.iter().find_map(|pred| match pred.skip_binders().skip_binders() {
|
|
// FIXME: how to correctly handle higher-ranked bounds here?
|
|
WhereClause::Implemented(tr) => search(
|
|
tr.clone()
|
|
.shifted_out_to(Interner, DebruijnIndex::ONE)
|
|
.expect("FIXME unexpected higher-ranked trait bound"),
|
|
),
|
|
_ => None,
|
|
});
|
|
if let Some(_) = res {
|
|
return res;
|
|
}
|
|
// Handle `Self::Type` referring to own associated type in trait definitions
|
|
if let GenericDefId::TraitId(trait_id) = param_id.parent() {
|
|
let generics = generics(db.upcast(), trait_id.into());
|
|
if generics.params.type_or_consts[param_id.local_id()].is_trait_self() {
|
|
let trait_ref = TyBuilder::trait_ref(db, trait_id)
|
|
.fill_with_bound_vars(DebruijnIndex::INNERMOST, 0)
|
|
.build();
|
|
return search(trait_ref);
|
|
}
|
|
}
|
|
None
|
|
}
|
|
_ => None,
|
|
}
|
|
}
|
|
|
|
/// Build the type of all specific fields of a struct or enum variant.
|
|
pub(crate) fn field_types_query(
|
|
db: &dyn HirDatabase,
|
|
variant_id: VariantId,
|
|
) -> Arc<ArenaMap<LocalFieldId, Binders<Ty>>> {
|
|
let var_data = variant_id.variant_data(db.upcast());
|
|
let (resolver, def): (_, GenericDefId) = match variant_id {
|
|
VariantId::StructId(it) => (it.resolver(db.upcast()), it.into()),
|
|
VariantId::UnionId(it) => (it.resolver(db.upcast()), it.into()),
|
|
VariantId::EnumVariantId(it) => (it.parent.resolver(db.upcast()), it.parent.into()),
|
|
};
|
|
let generics = generics(db.upcast(), def);
|
|
let mut res = ArenaMap::default();
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(ParamLoweringMode::Variable);
|
|
for (field_id, field_data) in var_data.fields().iter() {
|
|
res.insert(field_id, make_binders(db, &generics, ctx.lower_ty(&field_data.type_ref)));
|
|
}
|
|
Arc::new(res)
|
|
}
|
|
|
|
/// This query exists only to be used when resolving short-hand associated types
|
|
/// like `T::Item`.
|
|
///
|
|
/// See the analogous query in rustc and its comment:
|
|
/// <https://github.com/rust-lang/rust/blob/9150f844e2624eb013ec78ca08c1d416e6644026/src/librustc_typeck/astconv.rs#L46>
|
|
/// This is a query mostly to handle cycles somewhat gracefully; e.g. the
|
|
/// following bounds are disallowed: `T: Foo<U::Item>, U: Foo<T::Item>`, but
|
|
/// these are fine: `T: Foo<U::Item>, U: Foo<()>`.
|
|
pub(crate) fn generic_predicates_for_param_query(
|
|
db: &dyn HirDatabase,
|
|
def: GenericDefId,
|
|
param_id: TypeOrConstParamId,
|
|
assoc_name: Option<Name>,
|
|
) -> Arc<[Binders<QuantifiedWhereClause>]> {
|
|
let resolver = def.resolver(db.upcast());
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(ParamLoweringMode::Variable);
|
|
let generics = generics(db.upcast(), def);
|
|
let mut predicates: Vec<_> = resolver
|
|
.where_predicates_in_scope()
|
|
// we have to filter out all other predicates *first*, before attempting to lower them
|
|
.filter(|pred| match pred {
|
|
WherePredicate::ForLifetime { target, bound, .. }
|
|
| WherePredicate::TypeBound { target, bound, .. } => {
|
|
match target {
|
|
WherePredicateTypeTarget::TypeRef(type_ref) => {
|
|
if ctx.lower_ty_only_param(type_ref) != Some(param_id) {
|
|
return false;
|
|
}
|
|
}
|
|
&WherePredicateTypeTarget::TypeOrConstParam(local_id) => {
|
|
let target_id = TypeOrConstParamId { parent: def, local_id };
|
|
if target_id != param_id {
|
|
return false;
|
|
}
|
|
}
|
|
};
|
|
|
|
match &**bound {
|
|
TypeBound::ForLifetime(_, path) | TypeBound::Path(path, _) => {
|
|
// Only lower the bound if the trait could possibly define the associated
|
|
// type we're looking for.
|
|
|
|
let assoc_name = match &assoc_name {
|
|
Some(it) => it,
|
|
None => return true,
|
|
};
|
|
let tr = match resolver
|
|
.resolve_path_in_type_ns_fully(db.upcast(), path.mod_path())
|
|
{
|
|
Some(TypeNs::TraitId(tr)) => tr,
|
|
_ => return false,
|
|
};
|
|
|
|
all_super_traits(db.upcast(), tr).iter().any(|tr| {
|
|
db.trait_data(*tr).items.iter().any(|(name, item)| {
|
|
matches!(item, AssocItemId::TypeAliasId(_)) && name == assoc_name
|
|
})
|
|
})
|
|
}
|
|
TypeBound::Lifetime(_) | TypeBound::Error => false,
|
|
}
|
|
}
|
|
WherePredicate::Lifetime { .. } => false,
|
|
})
|
|
.flat_map(|pred| {
|
|
ctx.lower_where_predicate(pred, true).map(|p| make_binders(db, &generics, p))
|
|
})
|
|
.collect();
|
|
|
|
let subst = generics.bound_vars_subst(db, DebruijnIndex::INNERMOST);
|
|
let explicitly_unsized_tys = ctx.unsized_types.into_inner();
|
|
let implicitly_sized_predicates =
|
|
implicitly_sized_clauses(db, param_id.parent, &explicitly_unsized_tys, &subst, &resolver)
|
|
.map(|p| make_binders(db, &generics, crate::wrap_empty_binders(p)));
|
|
predicates.extend(implicitly_sized_predicates);
|
|
predicates.into()
|
|
}
|
|
|
|
pub(crate) fn generic_predicates_for_param_recover(
|
|
_db: &dyn HirDatabase,
|
|
_cycle: &[String],
|
|
_def: &GenericDefId,
|
|
_param_id: &TypeOrConstParamId,
|
|
_assoc_name: &Option<Name>,
|
|
) -> Arc<[Binders<QuantifiedWhereClause>]> {
|
|
Arc::new([])
|
|
}
|
|
|
|
pub(crate) fn trait_environment_query(
|
|
db: &dyn HirDatabase,
|
|
def: GenericDefId,
|
|
) -> Arc<TraitEnvironment> {
|
|
let resolver = def.resolver(db.upcast());
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(ParamLoweringMode::Placeholder);
|
|
let mut traits_in_scope = Vec::new();
|
|
let mut clauses = Vec::new();
|
|
for pred in resolver.where_predicates_in_scope() {
|
|
for pred in ctx.lower_where_predicate(pred, false) {
|
|
if let WhereClause::Implemented(tr) = &pred.skip_binders() {
|
|
traits_in_scope.push((tr.self_type_parameter(Interner).clone(), tr.hir_trait_id()));
|
|
}
|
|
let program_clause: chalk_ir::ProgramClause<Interner> = pred.cast(Interner);
|
|
clauses.push(program_clause.into_from_env_clause(Interner));
|
|
}
|
|
}
|
|
|
|
let container: Option<ItemContainerId> = match def {
|
|
// FIXME: is there a function for this?
|
|
GenericDefId::FunctionId(f) => Some(f.lookup(db.upcast()).container),
|
|
GenericDefId::AdtId(_) => None,
|
|
GenericDefId::TraitId(_) => None,
|
|
GenericDefId::TypeAliasId(t) => Some(t.lookup(db.upcast()).container),
|
|
GenericDefId::ImplId(_) => None,
|
|
GenericDefId::EnumVariantId(_) => None,
|
|
GenericDefId::ConstId(c) => Some(c.lookup(db.upcast()).container),
|
|
};
|
|
if let Some(ItemContainerId::TraitId(trait_id)) = container {
|
|
// add `Self: Trait<T1, T2, ...>` to the environment in trait
|
|
// function default implementations (and speculative code
|
|
// inside consts or type aliases)
|
|
cov_mark::hit!(trait_self_implements_self);
|
|
let substs = TyBuilder::placeholder_subst(db, trait_id);
|
|
let trait_ref = TraitRef { trait_id: to_chalk_trait_id(trait_id), substitution: substs };
|
|
let pred = WhereClause::Implemented(trait_ref);
|
|
let program_clause: chalk_ir::ProgramClause<Interner> = pred.cast(Interner);
|
|
clauses.push(program_clause.into_from_env_clause(Interner));
|
|
}
|
|
|
|
let subst = generics(db.upcast(), def).placeholder_subst(db);
|
|
let explicitly_unsized_tys = ctx.unsized_types.into_inner();
|
|
let implicitly_sized_clauses =
|
|
implicitly_sized_clauses(db, def, &explicitly_unsized_tys, &subst, &resolver).map(|pred| {
|
|
let program_clause: chalk_ir::ProgramClause<Interner> = pred.cast(Interner);
|
|
program_clause.into_from_env_clause(Interner)
|
|
});
|
|
clauses.extend(implicitly_sized_clauses);
|
|
|
|
let krate = def.module(db.upcast()).krate();
|
|
|
|
let env = chalk_ir::Environment::new(Interner).add_clauses(Interner, clauses);
|
|
|
|
Arc::new(TraitEnvironment { krate, traits_from_clauses: traits_in_scope, env })
|
|
}
|
|
|
|
/// Resolve the where clause(s) of an item with generics.
|
|
pub(crate) fn generic_predicates_query(
|
|
db: &dyn HirDatabase,
|
|
def: GenericDefId,
|
|
) -> Arc<[Binders<QuantifiedWhereClause>]> {
|
|
let resolver = def.resolver(db.upcast());
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(ParamLoweringMode::Variable);
|
|
let generics = generics(db.upcast(), def);
|
|
|
|
let mut predicates = resolver
|
|
.where_predicates_in_scope()
|
|
.flat_map(|pred| {
|
|
ctx.lower_where_predicate(pred, false).map(|p| make_binders(db, &generics, p))
|
|
})
|
|
.collect::<Vec<_>>();
|
|
|
|
let subst = generics.bound_vars_subst(db, DebruijnIndex::INNERMOST);
|
|
let explicitly_unsized_tys = ctx.unsized_types.into_inner();
|
|
let implicitly_sized_predicates =
|
|
implicitly_sized_clauses(db, def, &explicitly_unsized_tys, &subst, &resolver)
|
|
.map(|p| make_binders(db, &generics, crate::wrap_empty_binders(p)));
|
|
predicates.extend(implicitly_sized_predicates);
|
|
predicates.into()
|
|
}
|
|
|
|
/// Generate implicit `: Sized` predicates for all generics that has no `?Sized` bound.
|
|
/// Exception is Self of a trait def.
|
|
fn implicitly_sized_clauses<'a>(
|
|
db: &dyn HirDatabase,
|
|
def: GenericDefId,
|
|
explicitly_unsized_tys: &'a FxHashSet<Ty>,
|
|
substitution: &'a Substitution,
|
|
resolver: &Resolver,
|
|
) -> impl Iterator<Item = WhereClause> + 'a {
|
|
let is_trait_def = matches!(def, GenericDefId::TraitId(..));
|
|
let generic_args = &substitution.as_slice(Interner)[is_trait_def as usize..];
|
|
let sized_trait = db
|
|
.lang_item(resolver.krate(), SmolStr::new_inline("sized"))
|
|
.and_then(|lang_item| lang_item.as_trait().map(to_chalk_trait_id));
|
|
|
|
sized_trait.into_iter().flat_map(move |sized_trait| {
|
|
let implicitly_sized_tys = generic_args
|
|
.iter()
|
|
.filter_map(|generic_arg| generic_arg.ty(Interner))
|
|
.filter(move |&self_ty| !explicitly_unsized_tys.contains(self_ty));
|
|
implicitly_sized_tys.map(move |self_ty| {
|
|
WhereClause::Implemented(TraitRef {
|
|
trait_id: sized_trait,
|
|
substitution: Substitution::from1(Interner, self_ty.clone()),
|
|
})
|
|
})
|
|
})
|
|
}
|
|
|
|
/// Resolve the default type params from generics
|
|
pub(crate) fn generic_defaults_query(
|
|
db: &dyn HirDatabase,
|
|
def: GenericDefId,
|
|
) -> Arc<[Binders<chalk_ir::GenericArg<Interner>>]> {
|
|
let resolver = def.resolver(db.upcast());
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(ParamLoweringMode::Variable);
|
|
let generic_params = generics(db.upcast(), def);
|
|
|
|
let defaults = generic_params
|
|
.iter()
|
|
.enumerate()
|
|
.map(|(idx, (id, p))| {
|
|
let p = match p {
|
|
TypeOrConstParamData::TypeParamData(p) => p,
|
|
TypeOrConstParamData::ConstParamData(_) => {
|
|
// FIXME: implement const generic defaults
|
|
let val = unknown_const_as_generic(
|
|
db.const_param_ty(ConstParamId::from_unchecked(id)),
|
|
);
|
|
return crate::make_binders_with_count(db, idx, &generic_params, val);
|
|
}
|
|
};
|
|
let mut ty =
|
|
p.default.as_ref().map_or(TyKind::Error.intern(Interner), |t| ctx.lower_ty(t));
|
|
|
|
// Each default can only refer to previous parameters.
|
|
// type variable default referring to parameter coming
|
|
// after it. This is forbidden (FIXME: report
|
|
// diagnostic)
|
|
ty = fallback_bound_vars(ty, idx);
|
|
let val = GenericArgData::Ty(ty).intern(Interner);
|
|
crate::make_binders_with_count(db, idx, &generic_params, val)
|
|
})
|
|
.collect();
|
|
|
|
defaults
|
|
}
|
|
|
|
pub(crate) fn generic_defaults_recover(
|
|
db: &dyn HirDatabase,
|
|
_cycle: &[String],
|
|
def: &GenericDefId,
|
|
) -> Arc<[Binders<crate::GenericArg>]> {
|
|
let generic_params = generics(db.upcast(), *def);
|
|
// FIXME: this code is not covered in tests.
|
|
// we still need one default per parameter
|
|
let defaults = generic_params
|
|
.iter_id()
|
|
.enumerate()
|
|
.map(|(count, id)| {
|
|
let val = match id {
|
|
itertools::Either::Left(_) => {
|
|
GenericArgData::Ty(TyKind::Error.intern(Interner)).intern(Interner)
|
|
}
|
|
itertools::Either::Right(id) => unknown_const_as_generic(db.const_param_ty(id)),
|
|
};
|
|
crate::make_binders_with_count(db, count, &generic_params, val)
|
|
})
|
|
.collect();
|
|
|
|
defaults
|
|
}
|
|
|
|
fn fn_sig_for_fn(db: &dyn HirDatabase, def: FunctionId) -> PolyFnSig {
|
|
let data = db.function_data(def);
|
|
let resolver = def.resolver(db.upcast());
|
|
let ctx_params = TyLoweringContext::new(db, &resolver)
|
|
.with_impl_trait_mode(ImplTraitLoweringMode::Variable)
|
|
.with_type_param_mode(ParamLoweringMode::Variable);
|
|
let params = data.params.iter().map(|(_, tr)| ctx_params.lower_ty(tr)).collect::<Vec<_>>();
|
|
let ctx_ret = TyLoweringContext::new(db, &resolver)
|
|
.with_impl_trait_mode(ImplTraitLoweringMode::Opaque)
|
|
.with_type_param_mode(ParamLoweringMode::Variable);
|
|
let ret = ctx_ret.lower_ty(&data.ret_type);
|
|
let generics = generics(db.upcast(), def.into());
|
|
let sig = CallableSig::from_params_and_return(params, ret, data.is_varargs());
|
|
make_binders(db, &generics, sig)
|
|
}
|
|
|
|
/// Build the declared type of a function. This should not need to look at the
|
|
/// function body.
|
|
fn type_for_fn(db: &dyn HirDatabase, def: FunctionId) -> Binders<Ty> {
|
|
let generics = generics(db.upcast(), def.into());
|
|
let substs = generics.bound_vars_subst(db, DebruijnIndex::INNERMOST);
|
|
make_binders(
|
|
db,
|
|
&generics,
|
|
TyKind::FnDef(CallableDefId::FunctionId(def).to_chalk(db), substs).intern(Interner),
|
|
)
|
|
}
|
|
|
|
/// Build the declared type of a const.
|
|
fn type_for_const(db: &dyn HirDatabase, def: ConstId) -> Binders<Ty> {
|
|
let data = db.const_data(def);
|
|
let generics = generics(db.upcast(), def.into());
|
|
let resolver = def.resolver(db.upcast());
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(ParamLoweringMode::Variable);
|
|
|
|
make_binders(db, &generics, ctx.lower_ty(&data.type_ref))
|
|
}
|
|
|
|
/// Build the declared type of a static.
|
|
fn type_for_static(db: &dyn HirDatabase, def: StaticId) -> Binders<Ty> {
|
|
let data = db.static_data(def);
|
|
let resolver = def.resolver(db.upcast());
|
|
let ctx = TyLoweringContext::new(db, &resolver);
|
|
|
|
Binders::empty(Interner, ctx.lower_ty(&data.type_ref))
|
|
}
|
|
|
|
fn fn_sig_for_struct_constructor(db: &dyn HirDatabase, def: StructId) -> PolyFnSig {
|
|
let struct_data = db.struct_data(def);
|
|
let fields = struct_data.variant_data.fields();
|
|
let resolver = def.resolver(db.upcast());
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(ParamLoweringMode::Variable);
|
|
let params = fields.iter().map(|(_, field)| ctx.lower_ty(&field.type_ref)).collect::<Vec<_>>();
|
|
let (ret, binders) = type_for_adt(db, def.into()).into_value_and_skipped_binders();
|
|
Binders::new(binders, CallableSig::from_params_and_return(params, ret, false))
|
|
}
|
|
|
|
/// Build the type of a tuple struct constructor.
|
|
fn type_for_struct_constructor(db: &dyn HirDatabase, def: StructId) -> Binders<Ty> {
|
|
let struct_data = db.struct_data(def);
|
|
if let StructKind::Unit = struct_data.variant_data.kind() {
|
|
return type_for_adt(db, def.into());
|
|
}
|
|
let generics = generics(db.upcast(), def.into());
|
|
let substs = generics.bound_vars_subst(db, DebruijnIndex::INNERMOST);
|
|
make_binders(
|
|
db,
|
|
&generics,
|
|
TyKind::FnDef(CallableDefId::StructId(def).to_chalk(db), substs).intern(Interner),
|
|
)
|
|
}
|
|
|
|
fn fn_sig_for_enum_variant_constructor(db: &dyn HirDatabase, def: EnumVariantId) -> PolyFnSig {
|
|
let enum_data = db.enum_data(def.parent);
|
|
let var_data = &enum_data.variants[def.local_id];
|
|
let fields = var_data.variant_data.fields();
|
|
let resolver = def.parent.resolver(db.upcast());
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(ParamLoweringMode::Variable);
|
|
let params = fields.iter().map(|(_, field)| ctx.lower_ty(&field.type_ref)).collect::<Vec<_>>();
|
|
let (ret, binders) = type_for_adt(db, def.parent.into()).into_value_and_skipped_binders();
|
|
Binders::new(binders, CallableSig::from_params_and_return(params, ret, false))
|
|
}
|
|
|
|
/// Build the type of a tuple enum variant constructor.
|
|
fn type_for_enum_variant_constructor(db: &dyn HirDatabase, def: EnumVariantId) -> Binders<Ty> {
|
|
let enum_data = db.enum_data(def.parent);
|
|
let var_data = &enum_data.variants[def.local_id].variant_data;
|
|
if let StructKind::Unit = var_data.kind() {
|
|
return type_for_adt(db, def.parent.into());
|
|
}
|
|
let generics = generics(db.upcast(), def.parent.into());
|
|
let substs = generics.bound_vars_subst(db, DebruijnIndex::INNERMOST);
|
|
make_binders(
|
|
db,
|
|
&generics,
|
|
TyKind::FnDef(CallableDefId::EnumVariantId(def).to_chalk(db), substs).intern(Interner),
|
|
)
|
|
}
|
|
|
|
fn type_for_adt(db: &dyn HirDatabase, adt: AdtId) -> Binders<Ty> {
|
|
let generics = generics(db.upcast(), adt.into());
|
|
let subst = generics.bound_vars_subst(db, DebruijnIndex::INNERMOST);
|
|
let ty = TyKind::Adt(crate::AdtId(adt), subst).intern(Interner);
|
|
make_binders(db, &generics, ty)
|
|
}
|
|
|
|
fn type_for_type_alias(db: &dyn HirDatabase, t: TypeAliasId) -> Binders<Ty> {
|
|
let generics = generics(db.upcast(), t.into());
|
|
let resolver = t.resolver(db.upcast());
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(ParamLoweringMode::Variable);
|
|
if db.type_alias_data(t).is_extern {
|
|
Binders::empty(Interner, TyKind::Foreign(crate::to_foreign_def_id(t)).intern(Interner))
|
|
} else {
|
|
let type_ref = &db.type_alias_data(t).type_ref;
|
|
let inner = ctx.lower_ty(type_ref.as_deref().unwrap_or(&TypeRef::Error));
|
|
make_binders(db, &generics, inner)
|
|
}
|
|
}
|
|
|
|
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
|
|
pub enum CallableDefId {
|
|
FunctionId(FunctionId),
|
|
StructId(StructId),
|
|
EnumVariantId(EnumVariantId),
|
|
}
|
|
impl_from!(FunctionId, StructId, EnumVariantId for CallableDefId);
|
|
|
|
impl CallableDefId {
|
|
pub fn krate(self, db: &dyn HirDatabase) -> CrateId {
|
|
let db = db.upcast();
|
|
match self {
|
|
CallableDefId::FunctionId(f) => f.lookup(db).module(db),
|
|
CallableDefId::StructId(s) => s.lookup(db).container,
|
|
CallableDefId::EnumVariantId(e) => e.parent.lookup(db).container,
|
|
}
|
|
.krate()
|
|
}
|
|
}
|
|
|
|
impl From<CallableDefId> for GenericDefId {
|
|
fn from(def: CallableDefId) -> GenericDefId {
|
|
match def {
|
|
CallableDefId::FunctionId(f) => f.into(),
|
|
CallableDefId::StructId(s) => s.into(),
|
|
CallableDefId::EnumVariantId(e) => e.into(),
|
|
}
|
|
}
|
|
}
|
|
|
|
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
|
|
pub enum TyDefId {
|
|
BuiltinType(BuiltinType),
|
|
AdtId(AdtId),
|
|
TypeAliasId(TypeAliasId),
|
|
}
|
|
impl_from!(BuiltinType, AdtId(StructId, EnumId, UnionId), TypeAliasId for TyDefId);
|
|
|
|
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
|
|
pub enum ValueTyDefId {
|
|
FunctionId(FunctionId),
|
|
StructId(StructId),
|
|
UnionId(UnionId),
|
|
EnumVariantId(EnumVariantId),
|
|
ConstId(ConstId),
|
|
StaticId(StaticId),
|
|
}
|
|
impl_from!(FunctionId, StructId, UnionId, EnumVariantId, ConstId, StaticId for ValueTyDefId);
|
|
|
|
/// Build the declared type of an item. This depends on the namespace; e.g. for
|
|
/// `struct Foo(usize)`, we have two types: The type of the struct itself, and
|
|
/// the constructor function `(usize) -> Foo` which lives in the values
|
|
/// namespace.
|
|
pub(crate) fn ty_query(db: &dyn HirDatabase, def: TyDefId) -> Binders<Ty> {
|
|
match def {
|
|
TyDefId::BuiltinType(it) => Binders::empty(Interner, TyBuilder::builtin(it)),
|
|
TyDefId::AdtId(it) => type_for_adt(db, it),
|
|
TyDefId::TypeAliasId(it) => type_for_type_alias(db, it),
|
|
}
|
|
}
|
|
|
|
pub(crate) fn ty_recover(db: &dyn HirDatabase, _cycle: &[String], def: &TyDefId) -> Binders<Ty> {
|
|
let generics = match *def {
|
|
TyDefId::BuiltinType(_) => return Binders::empty(Interner, TyKind::Error.intern(Interner)),
|
|
TyDefId::AdtId(it) => generics(db.upcast(), it.into()),
|
|
TyDefId::TypeAliasId(it) => generics(db.upcast(), it.into()),
|
|
};
|
|
make_binders(db, &generics, TyKind::Error.intern(Interner))
|
|
}
|
|
|
|
pub(crate) fn value_ty_query(db: &dyn HirDatabase, def: ValueTyDefId) -> Binders<Ty> {
|
|
match def {
|
|
ValueTyDefId::FunctionId(it) => type_for_fn(db, it),
|
|
ValueTyDefId::StructId(it) => type_for_struct_constructor(db, it),
|
|
ValueTyDefId::UnionId(it) => type_for_adt(db, it.into()),
|
|
ValueTyDefId::EnumVariantId(it) => type_for_enum_variant_constructor(db, it),
|
|
ValueTyDefId::ConstId(it) => type_for_const(db, it),
|
|
ValueTyDefId::StaticId(it) => type_for_static(db, it),
|
|
}
|
|
}
|
|
|
|
pub(crate) fn impl_self_ty_query(db: &dyn HirDatabase, impl_id: ImplId) -> Binders<Ty> {
|
|
let impl_loc = impl_id.lookup(db.upcast());
|
|
let impl_data = db.impl_data(impl_id);
|
|
let resolver = impl_id.resolver(db.upcast());
|
|
let _cx = stdx::panic_context::enter(format!(
|
|
"impl_self_ty_query({:?} -> {:?} -> {:?})",
|
|
impl_id, impl_loc, impl_data
|
|
));
|
|
let generics = generics(db.upcast(), impl_id.into());
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(ParamLoweringMode::Variable);
|
|
make_binders(db, &generics, ctx.lower_ty(&impl_data.self_ty))
|
|
}
|
|
|
|
// returns None if def is a type arg
|
|
pub(crate) fn const_param_ty_query(db: &dyn HirDatabase, def: ConstParamId) -> Ty {
|
|
let parent_data = db.generic_params(def.parent());
|
|
let data = &parent_data.type_or_consts[def.local_id()];
|
|
let resolver = def.parent().resolver(db.upcast());
|
|
let ctx = TyLoweringContext::new(db, &resolver);
|
|
match data {
|
|
TypeOrConstParamData::TypeParamData(_) => {
|
|
never!();
|
|
Ty::new(Interner, TyKind::Error)
|
|
}
|
|
TypeOrConstParamData::ConstParamData(d) => ctx.lower_ty(&d.ty),
|
|
}
|
|
}
|
|
|
|
pub(crate) fn impl_self_ty_recover(
|
|
db: &dyn HirDatabase,
|
|
_cycle: &[String],
|
|
impl_id: &ImplId,
|
|
) -> Binders<Ty> {
|
|
let generics = generics(db.upcast(), (*impl_id).into());
|
|
make_binders(db, &generics, TyKind::Error.intern(Interner))
|
|
}
|
|
|
|
pub(crate) fn impl_trait_query(db: &dyn HirDatabase, impl_id: ImplId) -> Option<Binders<TraitRef>> {
|
|
let impl_loc = impl_id.lookup(db.upcast());
|
|
let impl_data = db.impl_data(impl_id);
|
|
let resolver = impl_id.resolver(db.upcast());
|
|
let _cx = stdx::panic_context::enter(format!(
|
|
"impl_trait_query({:?} -> {:?} -> {:?})",
|
|
impl_id, impl_loc, impl_data
|
|
));
|
|
let ctx =
|
|
TyLoweringContext::new(db, &resolver).with_type_param_mode(ParamLoweringMode::Variable);
|
|
let (self_ty, binders) = db.impl_self_ty(impl_id).into_value_and_skipped_binders();
|
|
let target_trait = impl_data.target_trait.as_ref()?;
|
|
Some(Binders::new(binders, ctx.lower_trait_ref(target_trait, Some(self_ty))?))
|
|
}
|
|
|
|
pub(crate) fn return_type_impl_traits(
|
|
db: &dyn HirDatabase,
|
|
def: hir_def::FunctionId,
|
|
) -> Option<Arc<Binders<ReturnTypeImplTraits>>> {
|
|
// FIXME unify with fn_sig_for_fn instead of doing lowering twice, maybe
|
|
let data = db.function_data(def);
|
|
let resolver = def.resolver(db.upcast());
|
|
let ctx_ret = TyLoweringContext::new(db, &resolver)
|
|
.with_impl_trait_mode(ImplTraitLoweringMode::Opaque)
|
|
.with_type_param_mode(ParamLoweringMode::Variable);
|
|
let _ret = (&ctx_ret).lower_ty(&data.ret_type);
|
|
let generics = generics(db.upcast(), def.into());
|
|
let return_type_impl_traits =
|
|
ReturnTypeImplTraits { impl_traits: ctx_ret.opaque_type_data.into_inner() };
|
|
if return_type_impl_traits.impl_traits.is_empty() {
|
|
None
|
|
} else {
|
|
Some(Arc::new(make_binders(db, &generics, return_type_impl_traits)))
|
|
}
|
|
}
|
|
|
|
pub(crate) fn lower_to_chalk_mutability(m: hir_def::type_ref::Mutability) -> Mutability {
|
|
match m {
|
|
hir_def::type_ref::Mutability::Shared => Mutability::Not,
|
|
hir_def::type_ref::Mutability::Mut => Mutability::Mut,
|
|
}
|
|
}
|
|
|
|
/// Checks if the provided generic arg matches its expected kind, then lower them via
|
|
/// provided closures. Use unknown if there was kind mismatch.
|
|
///
|
|
/// Returns `Some` of the lowered generic arg. `None` if the provided arg is a lifetime.
|
|
pub(crate) fn generic_arg_to_chalk<'a, T>(
|
|
db: &dyn HirDatabase,
|
|
kind_id: Either<TypeParamId, ConstParamId>,
|
|
arg: &'a GenericArg,
|
|
this: &mut T,
|
|
for_type: impl FnOnce(&mut T, &TypeRef) -> Ty + 'a,
|
|
for_const: impl FnOnce(&mut T, &ConstScalarOrPath, Ty) -> Const + 'a,
|
|
) -> Option<crate::GenericArg> {
|
|
let kind = match kind_id {
|
|
Either::Left(_) => ParamKind::Type,
|
|
Either::Right(id) => {
|
|
let ty = db.const_param_ty(id);
|
|
ParamKind::Const(ty)
|
|
}
|
|
};
|
|
Some(match (arg, kind) {
|
|
(GenericArg::Type(type_ref), ParamKind::Type) => {
|
|
let ty = for_type(this, type_ref);
|
|
GenericArgData::Ty(ty).intern(Interner)
|
|
}
|
|
(GenericArg::Const(c), ParamKind::Const(c_ty)) => {
|
|
GenericArgData::Const(for_const(this, c, c_ty)).intern(Interner)
|
|
}
|
|
(GenericArg::Const(_), ParamKind::Type) => {
|
|
GenericArgData::Ty(TyKind::Error.intern(Interner)).intern(Interner)
|
|
}
|
|
(GenericArg::Type(t), ParamKind::Const(c_ty)) => {
|
|
// We want to recover simple idents, which parser detects them
|
|
// as types. Maybe here is not the best place to do it, but
|
|
// it works.
|
|
if let TypeRef::Path(p) = t {
|
|
let p = p.mod_path();
|
|
if p.kind == PathKind::Plain {
|
|
if let [n] = p.segments() {
|
|
let c = ConstScalarOrPath::Path(n.clone());
|
|
return Some(
|
|
GenericArgData::Const(for_const(this, &c, c_ty)).intern(Interner),
|
|
);
|
|
}
|
|
}
|
|
}
|
|
unknown_const_as_generic(c_ty)
|
|
}
|
|
(GenericArg::Lifetime(_), _) => return None,
|
|
})
|
|
}
|
|
|
|
pub(crate) fn const_or_path_to_chalk(
|
|
db: &dyn HirDatabase,
|
|
resolver: &Resolver,
|
|
expected_ty: Ty,
|
|
value: &ConstScalarOrPath,
|
|
mode: ParamLoweringMode,
|
|
args: impl FnOnce() -> Generics,
|
|
debruijn: DebruijnIndex,
|
|
) -> Const {
|
|
match value {
|
|
ConstScalarOrPath::Scalar(s) => intern_const_scalar(s.clone(), expected_ty),
|
|
ConstScalarOrPath::Path(n) => {
|
|
let path = ModPath::from_segments(PathKind::Plain, Some(n.clone()));
|
|
path_to_const(db, resolver, &path, mode, args, debruijn)
|
|
.unwrap_or_else(|| unknown_const(expected_ty))
|
|
}
|
|
}
|
|
}
|
|
|
|
/// This replaces any 'free' Bound vars in `s` (i.e. those with indices past
|
|
/// num_vars_to_keep) by `TyKind::Unknown`.
|
|
fn fallback_bound_vars<T: TypeFoldable<Interner> + HasInterner<Interner = Interner>>(
|
|
s: T,
|
|
num_vars_to_keep: usize,
|
|
) -> T {
|
|
crate::fold_free_vars(
|
|
s,
|
|
|bound, binders| {
|
|
if bound.index >= num_vars_to_keep && bound.debruijn == DebruijnIndex::INNERMOST {
|
|
TyKind::Error.intern(Interner)
|
|
} else {
|
|
bound.shifted_in_from(binders).to_ty(Interner)
|
|
}
|
|
},
|
|
|ty, bound, binders| {
|
|
if bound.index >= num_vars_to_keep && bound.debruijn == DebruijnIndex::INNERMOST {
|
|
unknown_const(ty.clone())
|
|
} else {
|
|
bound.shifted_in_from(binders).to_const(Interner, ty)
|
|
}
|
|
},
|
|
)
|
|
}
|