crates/hir_ty/src/chalk_ext.rs

   1 //! Various extensions traits for Chalk types.
   2
   3 use chalk_ir::{FloatTy, IntTy, Mutability, Scalar, UintTy};
   4 use hir_def::{
   5     builtin_type::{BuiltinFloat, BuiltinInt, BuiltinType, BuiltinUint},
   6     type_ref::Rawness,
   7     AssocContainerId, FunctionId, GenericDefId, HasModule, Lookup, TraitId,
   8 };
   9
  10 use crate::{
  11     db::HirDatabase, from_assoc_type_id, from_chalk_trait_id, from_foreign_def_id,
  12     from_placeholder_idx, to_chalk_trait_id, AdtId, AliasEq, AliasTy, Binders, CallableDefId,
  13     CallableSig, FnPointer, ImplTraitId, Interner, Lifetime, ProjectionTy, QuantifiedWhereClause,
  14     Substitution, TraitRef, Ty, TyBuilder, TyKind, WhereClause,
  15 };
  16
  17 pub trait TyExt {
  18     fn is_unit(&self) -> bool;
  19     fn is_never(&self) -> bool;
  20     fn is_unknown(&self) -> bool;
  21     fn is_ty_var(&self) -> bool;
  22
  23     fn as_adt(&self) -> Option<(hir_def::AdtId, &Substitution)>;
  24     fn as_builtin(&self) -> Option<BuiltinType>;
  25     fn as_tuple(&self) -> Option<&Substitution>;
  26     fn as_fn_def(&self, db: &dyn HirDatabase) -> Option<FunctionId>;
  27     fn as_reference(&self) -> Option<(&Ty, Lifetime, Mutability)>;
  28     fn as_reference_or_ptr(&self) -> Option<(&Ty, Rawness, Mutability)>;
  29     fn as_generic_def(&self, db: &dyn HirDatabase) -> Option<GenericDefId>;
  30
  31     fn callable_def(&self, db: &dyn HirDatabase) -> Option<CallableDefId>;
  32     fn callable_sig(&self, db: &dyn HirDatabase) -> Option<CallableSig>;
  33
  34     fn strip_references(&self) -> &Ty;
  35
  36     /// If this is a `dyn Trait`, returns that trait.
  37     fn dyn_trait(&self) -> Option<TraitId>;
  38
  39     fn impl_trait_bounds(&self, db: &dyn HirDatabase) -> Option<Vec<QuantifiedWhereClause>>;
  40     fn associated_type_parent_trait(&self, db: &dyn HirDatabase) -> Option<TraitId>;
  41
  42     /// FIXME: Get rid of this, it's not a good abstraction
  43     fn equals_ctor(&self, other: &Ty) -> bool;
  44 }
  45
  46 impl TyExt for Ty {
  47     fn is_unit(&self) -> bool {
  48         matches!(self.kind(&Interner), TyKind::Tuple(0, _))
  49     }
  50
  51     fn is_never(&self) -> bool {
  52         matches!(self.kind(&Interner), TyKind::Never)
  53     }
  54
  55     fn is_unknown(&self) -> bool {
  56         matches!(self.kind(&Interner), TyKind::Error)
  57     }
  58
  59     fn is_ty_var(&self) -> bool {
  60         matches!(self.kind(&Interner), TyKind::InferenceVar(_, _))
  61     }
  62
  63     fn as_adt(&self) -> Option<(hir_def::AdtId, &Substitution)> {
  64         match self.kind(&Interner) {
  65             TyKind::Adt(AdtId(adt), parameters) => Some((*adt, parameters)),
  66             _ => None,
  67         }
  68     }
  69
  70     fn as_builtin(&self) -> Option<BuiltinType> {
  71         match self.kind(&Interner) {
  72             TyKind::Str => Some(BuiltinType::Str),
  73             TyKind::Scalar(Scalar::Bool) => Some(BuiltinType::Bool),
  74             TyKind::Scalar(Scalar::Char) => Some(BuiltinType::Char),
  75             TyKind::Scalar(Scalar::Float(fty)) => Some(BuiltinType::Float(match fty {
  76                 FloatTy::F64 => BuiltinFloat::F64,
  77                 FloatTy::F32 => BuiltinFloat::F32,
  78             })),
  79             TyKind::Scalar(Scalar::Int(ity)) => Some(BuiltinType::Int(match ity {
  80                 IntTy::Isize => BuiltinInt::Isize,
  81                 IntTy::I8 => BuiltinInt::I8,
  82                 IntTy::I16 => BuiltinInt::I16,
  83                 IntTy::I32 => BuiltinInt::I32,
  84                 IntTy::I64 => BuiltinInt::I64,
  85                 IntTy::I128 => BuiltinInt::I128,
  86             })),
  87             TyKind::Scalar(Scalar::Uint(ity)) => Some(BuiltinType::Uint(match ity {
  88                 UintTy::Usize => BuiltinUint::Usize,
  89                 UintTy::U8 => BuiltinUint::U8,
  90                 UintTy::U16 => BuiltinUint::U16,
  91                 UintTy::U32 => BuiltinUint::U32,
  92                 UintTy::U64 => BuiltinUint::U64,
  93                 UintTy::U128 => BuiltinUint::U128,
  94             })),
  95             _ => None,
  96         }
  97     }
  98
  99     fn as_tuple(&self) -> Option<&Substitution> {
 100         match self.kind(&Interner) {
 101             TyKind::Tuple(_, substs) => Some(substs),
 102             _ => None,
 103         }
 104     }
 105
 106     fn as_fn_def(&self, db: &dyn HirDatabase) -> Option<FunctionId> {
 107         if let Some(CallableDefId::FunctionId(func)) = self.callable_def(db) {
 108             Some(func)
 109         } else {
 110             None
 111         }
 112     }
 113     fn as_reference(&self) -> Option<(&Ty, Lifetime, Mutability)> {
 114         match self.kind(&Interner) {
 115             TyKind::Ref(mutability, lifetime, ty) => Some((ty, lifetime.clone(), *mutability)),
 116             _ => None,
 117         }
 118     }
 119
 120     fn as_reference_or_ptr(&self) -> Option<(&Ty, Rawness, Mutability)> {
 121         match self.kind(&Interner) {
 122             TyKind::Ref(mutability, _, ty) => Some((ty, Rawness::Ref, *mutability)),
 123             TyKind::Raw(mutability, ty) => Some((ty, Rawness::RawPtr, *mutability)),
 124             _ => None,
 125         }
 126     }
 127
 128     fn as_generic_def(&self, db: &dyn HirDatabase) -> Option<GenericDefId> {
 129         match *self.kind(&Interner) {
 130             TyKind::Adt(AdtId(adt), ..) => Some(adt.into()),
 131             TyKind::FnDef(callable, ..) => {
 132                 Some(db.lookup_intern_callable_def(callable.into()).into())
 133             }
 134             TyKind::AssociatedType(type_alias, ..) => Some(from_assoc_type_id(type_alias).into()),
 135             TyKind::Foreign(type_alias, ..) => Some(from_foreign_def_id(type_alias).into()),
 136             _ => None,
 137         }
 138     }
 139
 140     fn callable_def(&self, db: &dyn HirDatabase) -> Option<CallableDefId> {
 141         match self.kind(&Interner) {
 142             &TyKind::FnDef(def, ..) => Some(db.lookup_intern_callable_def(def.into())),
 143             _ => None,
 144         }
 145     }
 146
 147     fn callable_sig(&self, db: &dyn HirDatabase) -> Option<CallableSig> {
 148         match self.kind(&Interner) {
 149             TyKind::Function(fn_ptr) => Some(CallableSig::from_fn_ptr(fn_ptr)),
 150             TyKind::FnDef(def, parameters) => {
 151                 let callable_def = db.lookup_intern_callable_def((*def).into());
 152                 let sig = db.callable_item_signature(callable_def);
 153                 Some(sig.substitute(&Interner, &parameters))
 154             }
 155             TyKind::Closure(.., substs) => {
 156                 let sig_param = substs.at(&Interner, 0).assert_ty_ref(&Interner);
 157                 sig_param.callable_sig(db)
 158             }
 159             _ => None,
 160         }
 161     }
 162
 163     fn dyn_trait(&self) -> Option<TraitId> {
 164         let trait_ref = match self.kind(&Interner) {
 165             TyKind::Dyn(dyn_ty) => dyn_ty.bounds.skip_binders().interned().get(0).and_then(|b| {
 166                 match b.skip_binders() {
 167                     WhereClause::Implemented(trait_ref) => Some(trait_ref),
 168                     _ => None,
 169                 }
 170             }),
 171             _ => None,
 172         }?;
 173         Some(from_chalk_trait_id(trait_ref.trait_id))
 174     }
 175
 176     fn strip_references(&self) -> &Ty {
 177         let mut t: &Ty = self;
 178         while let TyKind::Ref(_mutability, _lifetime, ty) = t.kind(&Interner) {
 179             t = ty;
 180         }
 181         t
 182     }
 183
 184     fn impl_trait_bounds(&self, db: &dyn HirDatabase) -> Option<Vec<QuantifiedWhereClause>> {
 185         match self.kind(&Interner) {
 186             TyKind::OpaqueType(opaque_ty_id, ..) => {
 187                 match db.lookup_intern_impl_trait_id((*opaque_ty_id).into()) {
 188                     ImplTraitId::AsyncBlockTypeImplTrait(def, _expr) => {
 189                         let krate = def.module(db.upcast()).krate();
 190                         if let Some(future_trait) = db
 191                             .lang_item(krate, "future_trait".into())
 192                             .and_then(|item| item.as_trait())
 193                         {
 194                             // This is only used by type walking.
 195                             // Parameters will be walked outside, and projection predicate is not used.
 196                             // So just provide the Future trait.
 197                             let impl_bound = Binders::empty(
 198                                 &Interner,
 199                                 WhereClause::Implemented(TraitRef {
 200                                     trait_id: to_chalk_trait_id(future_trait),
 201                                     substitution: Substitution::empty(&Interner),
 202                                 }),
 203                             );
 204                             Some(vec![impl_bound])
 205                         } else {
 206                             None
 207                         }
 208                     }
 209                     ImplTraitId::ReturnTypeImplTrait(..) => None,
 210                 }
 211             }
 212             TyKind::Alias(AliasTy::Opaque(opaque_ty)) => {
 213                 let predicates = match db.lookup_intern_impl_trait_id(opaque_ty.opaque_ty_id.into())
 214                 {
 215                     ImplTraitId::ReturnTypeImplTrait(func, idx) => {
 216                         db.return_type_impl_traits(func).map(|it| {
 217                             let data = (*it)
 218                                 .as_ref()
 219                                 .map(|rpit| rpit.impl_traits[idx as usize].bounds.clone());
 220                             data.substitute(&Interner, &opaque_ty.substitution)
 221                         })
 222                     }
 223                     // It always has an parameter for Future::Output type.
 224                     ImplTraitId::AsyncBlockTypeImplTrait(..) => unreachable!(),
 225                 };
 226
 227                 predicates.map(|it| it.into_value_and_skipped_binders().0)
 228             }
 229             TyKind::Placeholder(idx) => {
 230                 let id = from_placeholder_idx(db, *idx);
 231                 let generic_params = db.generic_params(id.parent);
 232                 let param_data = &generic_params.types[id.local_id];
 233                 match param_data.provenance {
 234                     hir_def::generics::TypeParamProvenance::ArgumentImplTrait => {
 235                         let substs = TyBuilder::type_params_subst(db, id.parent);
 236                         let predicates = db
 237                             .generic_predicates(id.parent)
 238                             .into_iter()
 239                             .map(|pred| pred.clone().substitute(&Interner, &substs))
 240                             .filter(|wc| match &wc.skip_binders() {
 241                                 WhereClause::Implemented(tr) => {
 242                                     &tr.self_type_parameter(&Interner) == self
 243                                 }
 244                                 WhereClause::AliasEq(AliasEq {
 245                                     alias: AliasTy::Projection(proj),
 246                                     ty: _,
 247                                 }) => &proj.self_type_parameter(&Interner) == self,
 248                                 _ => false,
 249                             })
 250                             .collect::<Vec<_>>();
 251
 252                         Some(predicates)
 253                     }
 254                     _ => None,
 255                 }
 256             }
 257             _ => None,
 258         }
 259     }
 260
 261     fn associated_type_parent_trait(&self, db: &dyn HirDatabase) -> Option<TraitId> {
 262         match self.kind(&Interner) {
 263             TyKind::AssociatedType(id, ..) => {
 264                 match from_assoc_type_id(*id).lookup(db.upcast()).container {
 265                     AssocContainerId::TraitId(trait_id) => Some(trait_id),
 266                     _ => None,
 267                 }
 268             }
 269             TyKind::Alias(AliasTy::Projection(projection_ty)) => {
 270                 match from_assoc_type_id(projection_ty.associated_ty_id)
 271                     .lookup(db.upcast())
 272                     .container
 273                 {
 274                     AssocContainerId::TraitId(trait_id) => Some(trait_id),
 275                     _ => None,
 276                 }
 277             }
 278             _ => None,
 279         }
 280     }
 281
 282     fn equals_ctor(&self, other: &Ty) -> bool {
 283         match (self.kind(&Interner), other.kind(&Interner)) {
 284             (TyKind::Adt(adt, ..), TyKind::Adt(adt2, ..)) => adt == adt2,
 285             (TyKind::Slice(_), TyKind::Slice(_)) | (TyKind::Array(_, _), TyKind::Array(_, _)) => {
 286                 true
 287             }
 288             (TyKind::FnDef(def_id, ..), TyKind::FnDef(def_id2, ..)) => def_id == def_id2,
 289             (TyKind::OpaqueType(ty_id, ..), TyKind::OpaqueType(ty_id2, ..)) => ty_id == ty_id2,
 290             (TyKind::AssociatedType(ty_id, ..), TyKind::AssociatedType(ty_id2, ..)) => {
 291                 ty_id == ty_id2
 292             }
 293             (TyKind::Foreign(ty_id, ..), TyKind::Foreign(ty_id2, ..)) => ty_id == ty_id2,
 294             (TyKind::Closure(id1, _), TyKind::Closure(id2, _)) => id1 == id2,
 295             (TyKind::Ref(mutability, ..), TyKind::Ref(mutability2, ..))
 296             | (TyKind::Raw(mutability, ..), TyKind::Raw(mutability2, ..)) => {
 297                 mutability == mutability2
 298             }
 299             (
 300                 TyKind::Function(FnPointer { num_binders, sig, .. }),
 301                 TyKind::Function(FnPointer { num_binders: num_binders2, sig: sig2, .. }),
 302             ) => num_binders == num_binders2 && sig == sig2,
 303             (TyKind::Tuple(cardinality, _), TyKind::Tuple(cardinality2, _)) => {
 304                 cardinality == cardinality2
 305             }
 306             (TyKind::Str, TyKind::Str) | (TyKind::Never, TyKind::Never) => true,
 307             (TyKind::Scalar(scalar), TyKind::Scalar(scalar2)) => scalar == scalar2,
 308             _ => false,
 309         }
 310     }
 311 }
 312
 313 pub trait ProjectionTyExt {
 314     fn trait_ref(&self, db: &dyn HirDatabase) -> TraitRef;
 315     fn trait_(&self, db: &dyn HirDatabase) -> TraitId;
 316 }
 317
 318 impl ProjectionTyExt for ProjectionTy {
 319     fn trait_ref(&self, db: &dyn HirDatabase) -> TraitRef {
 320         TraitRef {
 321             trait_id: to_chalk_trait_id(self.trait_(db)),
 322             substitution: self.substitution.clone(),
 323         }
 324     }
 325
 326     fn trait_(&self, db: &dyn HirDatabase) -> TraitId {
 327         match from_assoc_type_id(self.associated_ty_id).lookup(db.upcast()).container {
 328             AssocContainerId::TraitId(it) => it,
 329             _ => panic!("projection ty without parent trait"),
 330         }
 331     }
 332 }
 333
 334 pub trait TraitRefExt {
 335     fn hir_trait_id(&self) -> TraitId;
 336 }
 337
 338 impl TraitRefExt for TraitRef {
 339     fn hir_trait_id(&self) -> TraitId {
 340         from_chalk_trait_id(self.trait_id)
 341     }
 342 }