aboutsummaryrefslogtreecommitdiff
path: root/crates/hir_ty/src/lib.rs
blob: 128cae830ffc061816c3f607154360c6c9ba7a30 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
//! The type system. We currently use this to infer types for completion, hover
//! information and various assists.

#[allow(unused)]
macro_rules! eprintln {
    ($($tt:tt)*) => { stdx::eprintln!($($tt)*) };
}

mod autoderef;
mod builder;
mod chalk_db;
mod chalk_ext;
pub mod consteval;
mod infer;
mod interner;
mod lower;
mod mapping;
mod op;
mod tls;
mod utils;
mod walk;
pub mod db;
pub mod diagnostics;
pub mod display;
pub mod method_resolution;
pub mod primitive;
pub mod traits;

#[cfg(test)]
mod tests;
#[cfg(test)]
mod test_db;

use std::sync::Arc;

use chalk_ir::{
    fold::{Fold, Shift},
    interner::HasInterner,
    UintTy,
};
use hir_def::{
    expr::ExprId,
    type_ref::{ConstScalar, Rawness},
    TypeParamId,
};

use crate::{db::HirDatabase, utils::generics};

pub use autoderef::autoderef;
pub use builder::TyBuilder;
pub use chalk_ext::*;
pub use infer::{could_unify, InferenceDiagnostic, InferenceResult};
pub use interner::Interner;
pub use lower::{
    associated_type_shorthand_candidates, callable_item_sig, CallableDefId, ImplTraitLoweringMode,
    TyDefId, TyLoweringContext, ValueTyDefId,
};
pub use mapping::{
    const_from_placeholder_idx, from_assoc_type_id, from_chalk_trait_id, from_foreign_def_id,
    from_placeholder_idx, lt_from_placeholder_idx, to_assoc_type_id, to_chalk_trait_id,
    to_foreign_def_id, to_placeholder_idx,
};
pub use traits::TraitEnvironment;
pub use utils::all_super_traits;
pub use walk::TypeWalk;

pub use chalk_ir::{
    cast::Cast, AdtId, BoundVar, DebruijnIndex, Mutability, Safety, Scalar, TyVariableKind,
};

pub type ForeignDefId = chalk_ir::ForeignDefId<Interner>;
pub type AssocTypeId = chalk_ir::AssocTypeId<Interner>;
pub type FnDefId = chalk_ir::FnDefId<Interner>;
pub type ClosureId = chalk_ir::ClosureId<Interner>;
pub type OpaqueTyId = chalk_ir::OpaqueTyId<Interner>;
pub type PlaceholderIndex = chalk_ir::PlaceholderIndex;

pub type VariableKind = chalk_ir::VariableKind<Interner>;
pub type VariableKinds = chalk_ir::VariableKinds<Interner>;
pub type CanonicalVarKinds = chalk_ir::CanonicalVarKinds<Interner>;
pub type Binders<T> = chalk_ir::Binders<T>;
pub type Substitution = chalk_ir::Substitution<Interner>;
pub type GenericArg = chalk_ir::GenericArg<Interner>;
pub type GenericArgData = chalk_ir::GenericArgData<Interner>;

pub type Ty = chalk_ir::Ty<Interner>;
pub type TyKind = chalk_ir::TyKind<Interner>;
pub type DynTy = chalk_ir::DynTy<Interner>;
pub type FnPointer = chalk_ir::FnPointer<Interner>;
// pub type FnSubst = chalk_ir::FnSubst<Interner>;
pub use chalk_ir::FnSubst;
pub type ProjectionTy = chalk_ir::ProjectionTy<Interner>;
pub type AliasTy = chalk_ir::AliasTy<Interner>;
pub type OpaqueTy = chalk_ir::OpaqueTy<Interner>;
pub type InferenceVar = chalk_ir::InferenceVar;

pub type Lifetime = chalk_ir::Lifetime<Interner>;
pub type LifetimeData = chalk_ir::LifetimeData<Interner>;
pub type LifetimeOutlives = chalk_ir::LifetimeOutlives<Interner>;

pub type Const = chalk_ir::Const<Interner>;
pub type ConstData = chalk_ir::ConstData<Interner>;
pub type ConstValue = chalk_ir::ConstValue<Interner>;
pub type ConcreteConst = chalk_ir::ConcreteConst<Interner>;

pub type ChalkTraitId = chalk_ir::TraitId<Interner>;
pub type TraitRef = chalk_ir::TraitRef<Interner>;
pub type QuantifiedWhereClause = Binders<WhereClause>;
pub type QuantifiedWhereClauses = chalk_ir::QuantifiedWhereClauses<Interner>;
pub type Canonical<T> = chalk_ir::Canonical<T>;

pub type FnSig = chalk_ir::FnSig<Interner>;

pub type InEnvironment<T> = chalk_ir::InEnvironment<T>;
pub type DomainGoal = chalk_ir::DomainGoal<Interner>;
pub type Goal = chalk_ir::Goal<Interner>;
pub type AliasEq = chalk_ir::AliasEq<Interner>;
pub type Solution = chalk_solve::Solution<Interner>;
pub type ConstrainedSubst = chalk_ir::ConstrainedSubst<Interner>;
pub type Guidance = chalk_solve::Guidance<Interner>;
pub type WhereClause = chalk_ir::WhereClause<Interner>;

// FIXME: get rid of this
pub fn subst_prefix(s: &Substitution, n: usize) -> Substitution {
    Substitution::from_iter(
        &Interner,
        s.as_slice(&Interner)[..std::cmp::min(s.len(&Interner), n)].iter().cloned(),
    )
}

/// Return an index of a parameter in the generic type parameter list by it's id.
pub fn param_idx(db: &dyn HirDatabase, id: TypeParamId) -> Option<usize> {
    generics(db.upcast(), id.parent).param_idx(id)
}

pub(crate) fn wrap_empty_binders<T>(value: T) -> Binders<T>
where
    T: Fold<Interner, Result = T> + HasInterner<Interner = Interner>,
{
    Binders::empty(&Interner, value.shifted_in_from(&Interner, DebruijnIndex::ONE))
}

pub(crate) fn make_only_type_binders<T: HasInterner<Interner = Interner>>(
    num_vars: usize,
    value: T,
) -> Binders<T> {
    Binders::new(
        VariableKinds::from_iter(
            &Interner,
            std::iter::repeat(chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General))
                .take(num_vars),
        ),
        value,
    )
}

// FIXME: get rid of this
pub fn make_canonical<T: HasInterner<Interner = Interner>>(
    value: T,
    kinds: impl IntoIterator<Item = TyVariableKind>,
) -> Canonical<T> {
    let kinds = kinds.into_iter().map(|tk| {
        chalk_ir::CanonicalVarKind::new(
            chalk_ir::VariableKind::Ty(tk),
            chalk_ir::UniverseIndex::ROOT,
        )
    });
    Canonical { value, binders: chalk_ir::CanonicalVarKinds::from_iter(&Interner, kinds) }
}

// FIXME: get rid of this, just replace it by FnPointer
/// A function signature as seen by type inference: Several parameter types and
/// one return type.
#[derive(Clone, PartialEq, Eq, Debug)]
pub struct CallableSig {
    params_and_return: Arc<[Ty]>,
    is_varargs: bool,
}

has_interner!(CallableSig);

/// A polymorphic function signature.
pub type PolyFnSig = Binders<CallableSig>;

impl CallableSig {
    pub fn from_params_and_return(mut params: Vec<Ty>, ret: Ty, is_varargs: bool) -> CallableSig {
        params.push(ret);
        CallableSig { params_and_return: params.into(), is_varargs }
    }

    pub fn from_fn_ptr(fn_ptr: &FnPointer) -> CallableSig {
        CallableSig {
            // FIXME: what to do about lifetime params? -> return PolyFnSig
            params_and_return: fn_ptr
                .substitution
                .clone()
                .shifted_out_to(&Interner, DebruijnIndex::ONE)
                .expect("unexpected lifetime vars in fn ptr")
                .0
                .as_slice(&Interner)
                .iter()
                .map(|arg| arg.assert_ty_ref(&Interner).clone())
                .collect(),
            is_varargs: fn_ptr.sig.variadic,
        }
    }

    pub fn to_fn_ptr(&self) -> FnPointer {
        FnPointer {
            num_binders: 0,
            sig: FnSig { abi: (), safety: Safety::Safe, variadic: self.is_varargs },
            substitution: FnSubst(Substitution::from_iter(
                &Interner,
                self.params_and_return.iter().cloned(),
            )),
        }
    }

    pub fn params(&self) -> &[Ty] {
        &self.params_and_return[0..self.params_and_return.len() - 1]
    }

    pub fn ret(&self) -> &Ty {
        &self.params_and_return[self.params_and_return.len() - 1]
    }
}

impl Fold<Interner> for CallableSig {
    type Result = CallableSig;

    fn fold_with<'i>(
        self,
        folder: &mut dyn chalk_ir::fold::Folder<'i, Interner>,
        outer_binder: DebruijnIndex,
    ) -> chalk_ir::Fallible<Self::Result>
    where
        Interner: 'i,
    {
        let vec = self.params_and_return.to_vec();
        let folded = vec.fold_with(folder, outer_binder)?;
        Ok(CallableSig { params_and_return: folded.into(), is_varargs: self.is_varargs })
    }
}

#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
pub enum ImplTraitId {
    ReturnTypeImplTrait(hir_def::FunctionId, u16),
    AsyncBlockTypeImplTrait(hir_def::DefWithBodyId, ExprId),
}

#[derive(Clone, PartialEq, Eq, Debug, Hash)]
pub struct ReturnTypeImplTraits {
    pub(crate) impl_traits: Vec<ReturnTypeImplTrait>,
}

has_interner!(ReturnTypeImplTraits);

#[derive(Clone, PartialEq, Eq, Debug, Hash)]
pub(crate) struct ReturnTypeImplTrait {
    pub(crate) bounds: Binders<Vec<QuantifiedWhereClause>>,
}

pub fn static_lifetime() -> Lifetime {
    LifetimeData::Static.intern(&Interner)
}

pub fn dummy_usize_const() -> Const {
    let usize_ty = chalk_ir::TyKind::Scalar(Scalar::Uint(UintTy::Usize)).intern(&Interner);
    chalk_ir::ConstData {
        ty: usize_ty,
        value: chalk_ir::ConstValue::Concrete(chalk_ir::ConcreteConst {
            interned: ConstScalar::Unknown,
        }),
    }
    .intern(&Interner)
}

pub(crate) fn fold_free_vars<T: HasInterner<Interner = Interner> + Fold<Interner>>(
    t: T,
    f: impl FnMut(BoundVar, DebruijnIndex) -> Ty,
) -> T::Result {
    use chalk_ir::{fold::Folder, Fallible};
    struct FreeVarFolder<F>(F);
    impl<'i, F: FnMut(BoundVar, DebruijnIndex) -> Ty + 'i> Folder<'i, Interner> for FreeVarFolder<F> {
        fn as_dyn(&mut self) -> &mut dyn Folder<'i, Interner> {
            self
        }

        fn interner(&self) -> &'i Interner {
            &Interner
        }

        fn fold_free_var_ty(
            &mut self,
            bound_var: BoundVar,
            outer_binder: DebruijnIndex,
        ) -> Fallible<Ty> {
            Ok(self.0(bound_var, outer_binder))
        }
    }
    t.fold_with(&mut FreeVarFolder(f), DebruijnIndex::INNERMOST).expect("fold failed unexpectedly")
}

pub(crate) fn fold_tys<T: HasInterner<Interner = Interner> + Fold<Interner>>(
    t: T,
    f: impl FnMut(Ty, DebruijnIndex) -> Ty,
    binders: DebruijnIndex,
) -> T::Result {
    use chalk_ir::{
        fold::{Folder, SuperFold},
        Fallible,
    };
    struct TyFolder<F>(F);
    impl<'i, F: FnMut(Ty, DebruijnIndex) -> Ty + 'i> Folder<'i, Interner> for TyFolder<F> {
        fn as_dyn(&mut self) -> &mut dyn Folder<'i, Interner> {
            self
        }

        fn interner(&self) -> &'i Interner {
            &Interner
        }

        fn fold_ty(&mut self, ty: Ty, outer_binder: DebruijnIndex) -> Fallible<Ty> {
            let ty = ty.super_fold_with(self.as_dyn(), outer_binder)?;
            Ok(self.0(ty, outer_binder))
        }
    }
    t.fold_with(&mut TyFolder(f), binders).expect("fold failed unexpectedly")
}

/// 'Canonicalizes' the `t` by replacing any errors with new variables. Also
/// ensures there are no unbound variables or inference variables anywhere in
/// the `t`.
pub fn replace_errors_with_variables<T>(t: &T) -> Canonical<T::Result>
where
    T: HasInterner<Interner = Interner> + Fold<Interner> + Clone,
    T::Result: HasInterner<Interner = Interner>,
{
    use chalk_ir::{
        fold::{Folder, SuperFold},
        Fallible, NoSolution,
    };
    struct ErrorReplacer {
        vars: usize,
    }
    impl<'i> Folder<'i, Interner> for ErrorReplacer {
        fn as_dyn(&mut self) -> &mut dyn Folder<'i, Interner> {
            self
        }

        fn interner(&self) -> &'i Interner {
            &Interner
        }

        fn fold_ty(&mut self, ty: Ty, outer_binder: DebruijnIndex) -> Fallible<Ty> {
            if let TyKind::Error = ty.kind(&Interner) {
                let index = self.vars;
                self.vars += 1;
                Ok(TyKind::BoundVar(BoundVar::new(outer_binder, index)).intern(&Interner))
            } else {
                let ty = ty.super_fold_with(self.as_dyn(), outer_binder)?;
                Ok(ty)
            }
        }

        fn fold_inference_ty(
            &mut self,
            _var: InferenceVar,
            _kind: TyVariableKind,
            _outer_binder: DebruijnIndex,
        ) -> Fallible<Ty> {
            if cfg!(debug_assertions) {
                // we don't want to just panic here, because then the error message
                // won't contain the whole thing, which would not be very helpful
                Err(NoSolution)
            } else {
                Ok(TyKind::Error.intern(&Interner))
            }
        }

        fn fold_free_var_ty(
            &mut self,
            _bound_var: BoundVar,
            _outer_binder: DebruijnIndex,
        ) -> Fallible<Ty> {
            if cfg!(debug_assertions) {
                // we don't want to just panic here, because then the error message
                // won't contain the whole thing, which would not be very helpful
                Err(NoSolution)
            } else {
                Ok(TyKind::Error.intern(&Interner))
            }
        }

        fn fold_inference_const(
            &mut self,
            _ty: Ty,
            _var: InferenceVar,
            _outer_binder: DebruijnIndex,
        ) -> Fallible<Const> {
            if cfg!(debug_assertions) {
                Err(NoSolution)
            } else {
                Ok(dummy_usize_const())
            }
        }

        fn fold_free_var_const(
            &mut self,
            _ty: Ty,
            _bound_var: BoundVar,
            _outer_binder: DebruijnIndex,
        ) -> Fallible<Const> {
            if cfg!(debug_assertions) {
                Err(NoSolution)
            } else {
                Ok(dummy_usize_const())
            }
        }

        fn fold_inference_lifetime(
            &mut self,
            _var: InferenceVar,
            _outer_binder: DebruijnIndex,
        ) -> Fallible<Lifetime> {
            if cfg!(debug_assertions) {
                Err(NoSolution)
            } else {
                Ok(static_lifetime())
            }
        }

        fn fold_free_var_lifetime(
            &mut self,
            _bound_var: BoundVar,
            _outer_binder: DebruijnIndex,
        ) -> Fallible<Lifetime> {
            if cfg!(debug_assertions) {
                Err(NoSolution)
            } else {
                Ok(static_lifetime())
            }
        }
    }
    let mut error_replacer = ErrorReplacer { vars: 0 };
    let value = match t.clone().fold_with(&mut error_replacer, DebruijnIndex::INNERMOST) {
        Ok(t) => t,
        Err(_) => panic!("Encountered unbound or inference vars in {:?}", t),
    };
    let kinds = (0..error_replacer.vars).map(|_| {
        chalk_ir::CanonicalVarKind::new(
            chalk_ir::VariableKind::Ty(TyVariableKind::General),
            chalk_ir::UniverseIndex::ROOT,
        )
    });
    Canonical { value, binders: chalk_ir::CanonicalVarKinds::from_iter(&Interner, kinds) }
}