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-rw-r--r--crates/ra_hir/src/ty/autoderef.rs103
-rw-r--r--crates/ra_hir/src/ty/display.rs93
-rw-r--r--crates/ra_hir/src/ty/infer.rs748
-rw-r--r--crates/ra_hir/src/ty/infer/coerce.rs339
-rw-r--r--crates/ra_hir/src/ty/infer/expr.rs667
-rw-r--r--crates/ra_hir/src/ty/infer/pat.rs183
-rw-r--r--crates/ra_hir/src/ty/infer/path.rs258
-rw-r--r--crates/ra_hir/src/ty/infer/unify.rs164
-rw-r--r--crates/ra_hir/src/ty/lower.rs831
-rw-r--r--crates/ra_hir/src/ty/method_resolution.rs375
-rw-r--r--crates/ra_hir/src/ty/op.rs52
-rw-r--r--crates/ra_hir/src/ty/primitive.rs160
-rw-r--r--crates/ra_hir/src/ty/tests.rs4895
-rw-r--r--crates/ra_hir/src/ty/tests/coercion.rs369
-rw-r--r--crates/ra_hir/src/ty/tests/never_type.rs246
-rw-r--r--crates/ra_hir/src/ty/traits.rs326
-rw-r--r--crates/ra_hir/src/ty/traits/chalk.rs884
17 files changed, 0 insertions, 10693 deletions
diff --git a/crates/ra_hir/src/ty/autoderef.rs b/crates/ra_hir/src/ty/autoderef.rs
deleted file mode 100644
index 41c99d227..000000000
--- a/crates/ra_hir/src/ty/autoderef.rs
+++ /dev/null
@@ -1,103 +0,0 @@
1//! In certain situations, rust automatically inserts derefs as necessary: for
2//! example, field accesses `foo.bar` still work when `foo` is actually a
3//! reference to a type with the field `bar`. This is an approximation of the
4//! logic in rustc (which lives in librustc_typeck/check/autoderef.rs).
5
6use std::iter::successors;
7
8use hir_def::{lang_item::LangItemTarget, resolver::Resolver};
9use hir_expand::name;
10use log::{info, warn};
11
12use crate::{db::HirDatabase, Trait};
13
14use super::{traits::Solution, Canonical, Substs, Ty, TypeWalk};
15
16const AUTODEREF_RECURSION_LIMIT: usize = 10;
17
18pub(crate) fn autoderef<'a>(
19 db: &'a impl HirDatabase,
20 resolver: &'a Resolver,
21 ty: Canonical<Ty>,
22) -> impl Iterator<Item = Canonical<Ty>> + 'a {
23 successors(Some(ty), move |ty| deref(db, resolver, ty)).take(AUTODEREF_RECURSION_LIMIT)
24}
25
26pub(crate) fn deref(
27 db: &impl HirDatabase,
28 resolver: &Resolver,
29 ty: &Canonical<Ty>,
30) -> Option<Canonical<Ty>> {
31 if let Some(derefed) = ty.value.builtin_deref() {
32 Some(Canonical { value: derefed, num_vars: ty.num_vars })
33 } else {
34 deref_by_trait(db, resolver, ty)
35 }
36}
37
38fn deref_by_trait(
39 db: &impl HirDatabase,
40 resolver: &Resolver,
41 ty: &Canonical<Ty>,
42) -> Option<Canonical<Ty>> {
43 let krate = resolver.krate()?;
44 let deref_trait = match db.lang_item(krate.into(), "deref".into())? {
45 LangItemTarget::TraitId(t) => Trait::from(t),
46 _ => return None,
47 };
48 let target = deref_trait.associated_type_by_name(db, &name::TARGET_TYPE)?;
49
50 let generic_params = db.generic_params(target.id.into());
51 if generic_params.count_params_including_parent() != 1 {
52 // the Target type + Deref trait should only have one generic parameter,
53 // namely Deref's Self type
54 return None;
55 }
56
57 // FIXME make the Canonical handling nicer
58
59 let env = super::lower::trait_env(db, resolver);
60
61 let parameters = Substs::build_for_generics(&generic_params)
62 .push(ty.value.clone().shift_bound_vars(1))
63 .build();
64
65 let projection = super::traits::ProjectionPredicate {
66 ty: Ty::Bound(0),
67 projection_ty: super::ProjectionTy { associated_ty: target, parameters },
68 };
69
70 let obligation = super::Obligation::Projection(projection);
71
72 let in_env = super::traits::InEnvironment { value: obligation, environment: env };
73
74 let canonical = super::Canonical { num_vars: 1 + ty.num_vars, value: in_env };
75
76 let solution = db.trait_solve(krate.into(), canonical)?;
77
78 match &solution {
79 Solution::Unique(vars) => {
80 // FIXME: vars may contain solutions for any inference variables
81 // that happened to be inside ty. To correctly handle these, we
82 // would have to pass the solution up to the inference context, but
83 // that requires a larger refactoring (especially if the deref
84 // happens during method resolution). So for the moment, we just
85 // check that we're not in the situation we're we would actually
86 // need to handle the values of the additional variables, i.e.
87 // they're just being 'passed through'. In the 'standard' case where
88 // we have `impl<T> Deref for Foo<T> { Target = T }`, that should be
89 // the case.
90 for i in 1..vars.0.num_vars {
91 if vars.0.value[i] != Ty::Bound((i - 1) as u32) {
92 warn!("complex solution for derefing {:?}: {:?}, ignoring", ty, solution);
93 return None;
94 }
95 }
96 Some(Canonical { value: vars.0.value[0].clone(), num_vars: vars.0.num_vars })
97 }
98 Solution::Ambig(_) => {
99 info!("Ambiguous solution for derefing {:?}: {:?}", ty, solution);
100 None
101 }
102 }
103}
diff --git a/crates/ra_hir/src/ty/display.rs b/crates/ra_hir/src/ty/display.rs
deleted file mode 100644
index 9bb3ece6c..000000000
--- a/crates/ra_hir/src/ty/display.rs
+++ /dev/null
@@ -1,93 +0,0 @@
1//! FIXME: write short doc here
2
3use std::fmt;
4
5use crate::db::HirDatabase;
6
7pub struct HirFormatter<'a, 'b, DB> {
8 pub db: &'a DB,
9 fmt: &'a mut fmt::Formatter<'b>,
10 buf: String,
11 curr_size: usize,
12 max_size: Option<usize>,
13}
14
15pub trait HirDisplay {
16 fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result;
17
18 fn display<'a, DB>(&'a self, db: &'a DB) -> HirDisplayWrapper<'a, DB, Self>
19 where
20 Self: Sized,
21 {
22 HirDisplayWrapper(db, self, None)
23 }
24
25 fn display_truncated<'a, DB>(
26 &'a self,
27 db: &'a DB,
28 max_size: Option<usize>,
29 ) -> HirDisplayWrapper<'a, DB, Self>
30 where
31 Self: Sized,
32 {
33 HirDisplayWrapper(db, self, max_size)
34 }
35}
36
37impl<'a, 'b, DB> HirFormatter<'a, 'b, DB>
38where
39 DB: HirDatabase,
40{
41 pub fn write_joined<T: HirDisplay>(
42 &mut self,
43 iter: impl IntoIterator<Item = T>,
44 sep: &str,
45 ) -> fmt::Result {
46 let mut first = true;
47 for e in iter {
48 if !first {
49 write!(self, "{}", sep)?;
50 }
51 first = false;
52 e.hir_fmt(self)?;
53 }
54 Ok(())
55 }
56
57 /// This allows using the `write!` macro directly with a `HirFormatter`.
58 pub fn write_fmt(&mut self, args: fmt::Arguments) -> fmt::Result {
59 // We write to a buffer first to track output size
60 self.buf.clear();
61 fmt::write(&mut self.buf, args)?;
62 self.curr_size += self.buf.len();
63
64 // Then we write to the internal formatter from the buffer
65 self.fmt.write_str(&self.buf)
66 }
67
68 pub fn should_truncate(&self) -> bool {
69 if let Some(max_size) = self.max_size {
70 self.curr_size >= max_size
71 } else {
72 false
73 }
74 }
75}
76
77pub struct HirDisplayWrapper<'a, DB, T>(&'a DB, &'a T, Option<usize>);
78
79impl<'a, DB, T> fmt::Display for HirDisplayWrapper<'a, DB, T>
80where
81 DB: HirDatabase,
82 T: HirDisplay,
83{
84 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
85 self.1.hir_fmt(&mut HirFormatter {
86 db: self.0,
87 fmt: f,
88 buf: String::with_capacity(20),
89 curr_size: 0,
90 max_size: self.2,
91 })
92 }
93}
diff --git a/crates/ra_hir/src/ty/infer.rs b/crates/ra_hir/src/ty/infer.rs
deleted file mode 100644
index ddc7d262a..000000000
--- a/crates/ra_hir/src/ty/infer.rs
+++ /dev/null
@@ -1,748 +0,0 @@
1//! Type inference, i.e. the process of walking through the code and determining
2//! the type of each expression and pattern.
3//!
4//! For type inference, compare the implementations in rustc (the various
5//! check_* methods in librustc_typeck/check/mod.rs are a good entry point) and
6//! IntelliJ-Rust (org.rust.lang.core.types.infer). Our entry point for
7//! inference here is the `infer` function, which infers the types of all
8//! expressions in a given function.
9//!
10//! During inference, types (i.e. the `Ty` struct) can contain type 'variables'
11//! which represent currently unknown types; as we walk through the expressions,
12//! we might determine that certain variables need to be equal to each other, or
13//! to certain types. To record this, we use the union-find implementation from
14//! the `ena` crate, which is extracted from rustc.
15
16use std::borrow::Cow;
17use std::mem;
18use std::ops::Index;
19use std::sync::Arc;
20
21use ena::unify::{InPlaceUnificationTable, NoError, UnifyKey, UnifyValue};
22use rustc_hash::FxHashMap;
23
24use hir_def::{
25 data::{ConstData, FunctionData},
26 path::known,
27 resolver::{HasResolver, Resolver, TypeNs},
28 type_ref::{Mutability, TypeRef},
29 AdtId, DefWithBodyId,
30};
31use hir_expand::{diagnostics::DiagnosticSink, name};
32use ra_arena::map::ArenaMap;
33use ra_prof::profile;
34use test_utils::tested_by;
35
36use super::{
37 lower,
38 traits::{Guidance, Obligation, ProjectionPredicate, Solution},
39 ApplicationTy, InEnvironment, ProjectionTy, Substs, TraitEnvironment, TraitRef, Ty, TypableDef,
40 TypeCtor, TypeWalk, Uncertain,
41};
42use crate::{
43 code_model::TypeAlias,
44 db::HirDatabase,
45 expr::{BindingAnnotation, Body, ExprId, PatId},
46 ty::infer::diagnostics::InferenceDiagnostic,
47 Adt, AssocItem, DefWithBody, FloatTy, Function, IntTy, Path, StructField, Trait, VariantDef,
48};
49
50macro_rules! ty_app {
51 ($ctor:pat, $param:pat) => {
52 crate::ty::Ty::Apply(crate::ty::ApplicationTy { ctor: $ctor, parameters: $param })
53 };
54 ($ctor:pat) => {
55 ty_app!($ctor, _)
56 };
57}
58
59mod unify;
60mod path;
61mod expr;
62mod pat;
63mod coerce;
64
65/// The entry point of type inference.
66pub fn infer_query(db: &impl HirDatabase, def: DefWithBody) -> Arc<InferenceResult> {
67 let _p = profile("infer_query");
68 let resolver = DefWithBodyId::from(def).resolver(db);
69 let mut ctx = InferenceContext::new(db, def, resolver);
70
71 match &def {
72 DefWithBody::Const(c) => ctx.collect_const(&db.const_data(c.id)),
73 DefWithBody::Function(f) => ctx.collect_fn(&db.function_data(f.id)),
74 DefWithBody::Static(s) => ctx.collect_const(&db.static_data(s.id)),
75 }
76
77 ctx.infer_body();
78
79 Arc::new(ctx.resolve_all())
80}
81
82#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
83enum ExprOrPatId {
84 ExprId(ExprId),
85 PatId(PatId),
86}
87
88impl_froms!(ExprOrPatId: ExprId, PatId);
89
90/// Binding modes inferred for patterns.
91/// https://doc.rust-lang.org/reference/patterns.html#binding-modes
92#[derive(Copy, Clone, Debug, Eq, PartialEq)]
93enum BindingMode {
94 Move,
95 Ref(Mutability),
96}
97
98impl BindingMode {
99 pub fn convert(annotation: BindingAnnotation) -> BindingMode {
100 match annotation {
101 BindingAnnotation::Unannotated | BindingAnnotation::Mutable => BindingMode::Move,
102 BindingAnnotation::Ref => BindingMode::Ref(Mutability::Shared),
103 BindingAnnotation::RefMut => BindingMode::Ref(Mutability::Mut),
104 }
105 }
106}
107
108impl Default for BindingMode {
109 fn default() -> Self {
110 BindingMode::Move
111 }
112}
113
114/// A mismatch between an expected and an inferred type.
115#[derive(Clone, PartialEq, Eq, Debug, Hash)]
116pub struct TypeMismatch {
117 pub expected: Ty,
118 pub actual: Ty,
119}
120
121/// The result of type inference: A mapping from expressions and patterns to types.
122#[derive(Clone, PartialEq, Eq, Debug, Default)]
123pub struct InferenceResult {
124 /// For each method call expr, records the function it resolves to.
125 method_resolutions: FxHashMap<ExprId, Function>,
126 /// For each field access expr, records the field it resolves to.
127 field_resolutions: FxHashMap<ExprId, StructField>,
128 /// For each field in record literal, records the field it resolves to.
129 record_field_resolutions: FxHashMap<ExprId, StructField>,
130 /// For each struct literal, records the variant it resolves to.
131 variant_resolutions: FxHashMap<ExprOrPatId, VariantDef>,
132 /// For each associated item record what it resolves to
133 assoc_resolutions: FxHashMap<ExprOrPatId, AssocItem>,
134 diagnostics: Vec<InferenceDiagnostic>,
135 pub(super) type_of_expr: ArenaMap<ExprId, Ty>,
136 pub(super) type_of_pat: ArenaMap<PatId, Ty>,
137 pub(super) type_mismatches: ArenaMap<ExprId, TypeMismatch>,
138}
139
140impl InferenceResult {
141 pub fn method_resolution(&self, expr: ExprId) -> Option<Function> {
142 self.method_resolutions.get(&expr).copied()
143 }
144 pub fn field_resolution(&self, expr: ExprId) -> Option<StructField> {
145 self.field_resolutions.get(&expr).copied()
146 }
147 pub fn record_field_resolution(&self, expr: ExprId) -> Option<StructField> {
148 self.record_field_resolutions.get(&expr).copied()
149 }
150 pub fn variant_resolution_for_expr(&self, id: ExprId) -> Option<VariantDef> {
151 self.variant_resolutions.get(&id.into()).copied()
152 }
153 pub fn variant_resolution_for_pat(&self, id: PatId) -> Option<VariantDef> {
154 self.variant_resolutions.get(&id.into()).copied()
155 }
156 pub fn assoc_resolutions_for_expr(&self, id: ExprId) -> Option<AssocItem> {
157 self.assoc_resolutions.get(&id.into()).copied()
158 }
159 pub fn assoc_resolutions_for_pat(&self, id: PatId) -> Option<AssocItem> {
160 self.assoc_resolutions.get(&id.into()).copied()
161 }
162 pub fn type_mismatch_for_expr(&self, expr: ExprId) -> Option<&TypeMismatch> {
163 self.type_mismatches.get(expr)
164 }
165 pub(crate) fn add_diagnostics(
166 &self,
167 db: &impl HirDatabase,
168 owner: Function,
169 sink: &mut DiagnosticSink,
170 ) {
171 self.diagnostics.iter().for_each(|it| it.add_to(db, owner, sink))
172 }
173}
174
175impl Index<ExprId> for InferenceResult {
176 type Output = Ty;
177
178 fn index(&self, expr: ExprId) -> &Ty {
179 self.type_of_expr.get(expr).unwrap_or(&Ty::Unknown)
180 }
181}
182
183impl Index<PatId> for InferenceResult {
184 type Output = Ty;
185
186 fn index(&self, pat: PatId) -> &Ty {
187 self.type_of_pat.get(pat).unwrap_or(&Ty::Unknown)
188 }
189}
190
191/// The inference context contains all information needed during type inference.
192#[derive(Clone, Debug)]
193struct InferenceContext<'a, D: HirDatabase> {
194 db: &'a D,
195 owner: DefWithBody,
196 body: Arc<Body>,
197 resolver: Resolver,
198 var_unification_table: InPlaceUnificationTable<TypeVarId>,
199 trait_env: Arc<TraitEnvironment>,
200 obligations: Vec<Obligation>,
201 result: InferenceResult,
202 /// The return type of the function being inferred.
203 return_ty: Ty,
204
205 /// Impls of `CoerceUnsized` used in coercion.
206 /// (from_ty_ctor, to_ty_ctor) => coerce_generic_index
207 // FIXME: Use trait solver for this.
208 // Chalk seems unable to work well with builtin impl of `Unsize` now.
209 coerce_unsized_map: FxHashMap<(TypeCtor, TypeCtor), usize>,
210}
211
212impl<'a, D: HirDatabase> InferenceContext<'a, D> {
213 fn new(db: &'a D, owner: DefWithBody, resolver: Resolver) -> Self {
214 InferenceContext {
215 result: InferenceResult::default(),
216 var_unification_table: InPlaceUnificationTable::new(),
217 obligations: Vec::default(),
218 return_ty: Ty::Unknown, // set in collect_fn_signature
219 trait_env: lower::trait_env(db, &resolver),
220 coerce_unsized_map: Self::init_coerce_unsized_map(db, &resolver),
221 db,
222 owner,
223 body: db.body(owner.into()),
224 resolver,
225 }
226 }
227
228 fn resolve_all(mut self) -> InferenceResult {
229 // FIXME resolve obligations as well (use Guidance if necessary)
230 let mut result = mem::replace(&mut self.result, InferenceResult::default());
231 let mut tv_stack = Vec::new();
232 for ty in result.type_of_expr.values_mut() {
233 let resolved = self.resolve_ty_completely(&mut tv_stack, mem::replace(ty, Ty::Unknown));
234 *ty = resolved;
235 }
236 for ty in result.type_of_pat.values_mut() {
237 let resolved = self.resolve_ty_completely(&mut tv_stack, mem::replace(ty, Ty::Unknown));
238 *ty = resolved;
239 }
240 result
241 }
242
243 fn write_expr_ty(&mut self, expr: ExprId, ty: Ty) {
244 self.result.type_of_expr.insert(expr, ty);
245 }
246
247 fn write_method_resolution(&mut self, expr: ExprId, func: Function) {
248 self.result.method_resolutions.insert(expr, func);
249 }
250
251 fn write_field_resolution(&mut self, expr: ExprId, field: StructField) {
252 self.result.field_resolutions.insert(expr, field);
253 }
254
255 fn write_variant_resolution(&mut self, id: ExprOrPatId, variant: VariantDef) {
256 self.result.variant_resolutions.insert(id, variant);
257 }
258
259 fn write_assoc_resolution(&mut self, id: ExprOrPatId, item: AssocItem) {
260 self.result.assoc_resolutions.insert(id, item);
261 }
262
263 fn write_pat_ty(&mut self, pat: PatId, ty: Ty) {
264 self.result.type_of_pat.insert(pat, ty);
265 }
266
267 fn push_diagnostic(&mut self, diagnostic: InferenceDiagnostic) {
268 self.result.diagnostics.push(diagnostic);
269 }
270
271 fn make_ty(&mut self, type_ref: &TypeRef) -> Ty {
272 let ty = Ty::from_hir(
273 self.db,
274 // FIXME use right resolver for block
275 &self.resolver,
276 type_ref,
277 );
278 let ty = self.insert_type_vars(ty);
279 self.normalize_associated_types_in(ty)
280 }
281
282 fn unify_substs(&mut self, substs1: &Substs, substs2: &Substs, depth: usize) -> bool {
283 substs1.0.iter().zip(substs2.0.iter()).all(|(t1, t2)| self.unify_inner(t1, t2, depth))
284 }
285
286 fn unify(&mut self, ty1: &Ty, ty2: &Ty) -> bool {
287 self.unify_inner(ty1, ty2, 0)
288 }
289
290 fn unify_inner(&mut self, ty1: &Ty, ty2: &Ty, depth: usize) -> bool {
291 if depth > 1000 {
292 // prevent stackoverflows
293 panic!("infinite recursion in unification");
294 }
295 if ty1 == ty2 {
296 return true;
297 }
298 // try to resolve type vars first
299 let ty1 = self.resolve_ty_shallow(ty1);
300 let ty2 = self.resolve_ty_shallow(ty2);
301 match (&*ty1, &*ty2) {
302 (Ty::Apply(a_ty1), Ty::Apply(a_ty2)) if a_ty1.ctor == a_ty2.ctor => {
303 self.unify_substs(&a_ty1.parameters, &a_ty2.parameters, depth + 1)
304 }
305 _ => self.unify_inner_trivial(&ty1, &ty2),
306 }
307 }
308
309 fn unify_inner_trivial(&mut self, ty1: &Ty, ty2: &Ty) -> bool {
310 match (ty1, ty2) {
311 (Ty::Unknown, _) | (_, Ty::Unknown) => true,
312
313 (Ty::Infer(InferTy::TypeVar(tv1)), Ty::Infer(InferTy::TypeVar(tv2)))
314 | (Ty::Infer(InferTy::IntVar(tv1)), Ty::Infer(InferTy::IntVar(tv2)))
315 | (Ty::Infer(InferTy::FloatVar(tv1)), Ty::Infer(InferTy::FloatVar(tv2)))
316 | (
317 Ty::Infer(InferTy::MaybeNeverTypeVar(tv1)),
318 Ty::Infer(InferTy::MaybeNeverTypeVar(tv2)),
319 ) => {
320 // both type vars are unknown since we tried to resolve them
321 self.var_unification_table.union(*tv1, *tv2);
322 true
323 }
324
325 // The order of MaybeNeverTypeVar matters here.
326 // Unifying MaybeNeverTypeVar and TypeVar will let the latter become MaybeNeverTypeVar.
327 // Unifying MaybeNeverTypeVar and other concrete type will let the former become it.
328 (Ty::Infer(InferTy::TypeVar(tv)), other)
329 | (other, Ty::Infer(InferTy::TypeVar(tv)))
330 | (Ty::Infer(InferTy::MaybeNeverTypeVar(tv)), other)
331 | (other, Ty::Infer(InferTy::MaybeNeverTypeVar(tv)))
332 | (Ty::Infer(InferTy::IntVar(tv)), other @ ty_app!(TypeCtor::Int(_)))
333 | (other @ ty_app!(TypeCtor::Int(_)), Ty::Infer(InferTy::IntVar(tv)))
334 | (Ty::Infer(InferTy::FloatVar(tv)), other @ ty_app!(TypeCtor::Float(_)))
335 | (other @ ty_app!(TypeCtor::Float(_)), Ty::Infer(InferTy::FloatVar(tv))) => {
336 // the type var is unknown since we tried to resolve it
337 self.var_unification_table.union_value(*tv, TypeVarValue::Known(other.clone()));
338 true
339 }
340
341 _ => false,
342 }
343 }
344
345 fn new_type_var(&mut self) -> Ty {
346 Ty::Infer(InferTy::TypeVar(self.var_unification_table.new_key(TypeVarValue::Unknown)))
347 }
348
349 fn new_integer_var(&mut self) -> Ty {
350 Ty::Infer(InferTy::IntVar(self.var_unification_table.new_key(TypeVarValue::Unknown)))
351 }
352
353 fn new_float_var(&mut self) -> Ty {
354 Ty::Infer(InferTy::FloatVar(self.var_unification_table.new_key(TypeVarValue::Unknown)))
355 }
356
357 fn new_maybe_never_type_var(&mut self) -> Ty {
358 Ty::Infer(InferTy::MaybeNeverTypeVar(
359 self.var_unification_table.new_key(TypeVarValue::Unknown),
360 ))
361 }
362
363 /// Replaces Ty::Unknown by a new type var, so we can maybe still infer it.
364 fn insert_type_vars_shallow(&mut self, ty: Ty) -> Ty {
365 match ty {
366 Ty::Unknown => self.new_type_var(),
367 Ty::Apply(ApplicationTy { ctor: TypeCtor::Int(Uncertain::Unknown), .. }) => {
368 self.new_integer_var()
369 }
370 Ty::Apply(ApplicationTy { ctor: TypeCtor::Float(Uncertain::Unknown), .. }) => {
371 self.new_float_var()
372 }
373 _ => ty,
374 }
375 }
376
377 fn insert_type_vars(&mut self, ty: Ty) -> Ty {
378 ty.fold(&mut |ty| self.insert_type_vars_shallow(ty))
379 }
380
381 fn resolve_obligations_as_possible(&mut self) {
382 let obligations = mem::replace(&mut self.obligations, Vec::new());
383 for obligation in obligations {
384 let in_env = InEnvironment::new(self.trait_env.clone(), obligation.clone());
385 let canonicalized = self.canonicalizer().canonicalize_obligation(in_env);
386 let solution = self
387 .db
388 .trait_solve(self.resolver.krate().unwrap().into(), canonicalized.value.clone());
389
390 match solution {
391 Some(Solution::Unique(substs)) => {
392 canonicalized.apply_solution(self, substs.0);
393 }
394 Some(Solution::Ambig(Guidance::Definite(substs))) => {
395 canonicalized.apply_solution(self, substs.0);
396 self.obligations.push(obligation);
397 }
398 Some(_) => {
399 // FIXME use this when trying to resolve everything at the end
400 self.obligations.push(obligation);
401 }
402 None => {
403 // FIXME obligation cannot be fulfilled => diagnostic
404 }
405 };
406 }
407 }
408
409 /// Resolves the type as far as currently possible, replacing type variables
410 /// by their known types. All types returned by the infer_* functions should
411 /// be resolved as far as possible, i.e. contain no type variables with
412 /// known type.
413 fn resolve_ty_as_possible(&mut self, tv_stack: &mut Vec<TypeVarId>, ty: Ty) -> Ty {
414 self.resolve_obligations_as_possible();
415
416 ty.fold(&mut |ty| match ty {
417 Ty::Infer(tv) => {
418 let inner = tv.to_inner();
419 if tv_stack.contains(&inner) {
420 tested_by!(type_var_cycles_resolve_as_possible);
421 // recursive type
422 return tv.fallback_value();
423 }
424 if let Some(known_ty) =
425 self.var_unification_table.inlined_probe_value(inner).known()
426 {
427 // known_ty may contain other variables that are known by now
428 tv_stack.push(inner);
429 let result = self.resolve_ty_as_possible(tv_stack, known_ty.clone());
430 tv_stack.pop();
431 result
432 } else {
433 ty
434 }
435 }
436 _ => ty,
437 })
438 }
439
440 /// If `ty` is a type variable with known type, returns that type;
441 /// otherwise, return ty.
442 fn resolve_ty_shallow<'b>(&mut self, ty: &'b Ty) -> Cow<'b, Ty> {
443 let mut ty = Cow::Borrowed(ty);
444 // The type variable could resolve to a int/float variable. Hence try
445 // resolving up to three times; each type of variable shouldn't occur
446 // more than once
447 for i in 0..3 {
448 if i > 0 {
449 tested_by!(type_var_resolves_to_int_var);
450 }
451 match &*ty {
452 Ty::Infer(tv) => {
453 let inner = tv.to_inner();
454 match self.var_unification_table.inlined_probe_value(inner).known() {
455 Some(known_ty) => {
456 // The known_ty can't be a type var itself
457 ty = Cow::Owned(known_ty.clone());
458 }
459 _ => return ty,
460 }
461 }
462 _ => return ty,
463 }
464 }
465 log::error!("Inference variable still not resolved: {:?}", ty);
466 ty
467 }
468
469 /// Recurses through the given type, normalizing associated types mentioned
470 /// in it by replacing them by type variables and registering obligations to
471 /// resolve later. This should be done once for every type we get from some
472 /// type annotation (e.g. from a let type annotation, field type or function
473 /// call). `make_ty` handles this already, but e.g. for field types we need
474 /// to do it as well.
475 fn normalize_associated_types_in(&mut self, ty: Ty) -> Ty {
476 let ty = self.resolve_ty_as_possible(&mut vec![], ty);
477 ty.fold(&mut |ty| match ty {
478 Ty::Projection(proj_ty) => self.normalize_projection_ty(proj_ty),
479 _ => ty,
480 })
481 }
482
483 fn normalize_projection_ty(&mut self, proj_ty: ProjectionTy) -> Ty {
484 let var = self.new_type_var();
485 let predicate = ProjectionPredicate { projection_ty: proj_ty, ty: var.clone() };
486 let obligation = Obligation::Projection(predicate);
487 self.obligations.push(obligation);
488 var
489 }
490
491 /// Resolves the type completely; type variables without known type are
492 /// replaced by Ty::Unknown.
493 fn resolve_ty_completely(&mut self, tv_stack: &mut Vec<TypeVarId>, ty: Ty) -> Ty {
494 ty.fold(&mut |ty| match ty {
495 Ty::Infer(tv) => {
496 let inner = tv.to_inner();
497 if tv_stack.contains(&inner) {
498 tested_by!(type_var_cycles_resolve_completely);
499 // recursive type
500 return tv.fallback_value();
501 }
502 if let Some(known_ty) =
503 self.var_unification_table.inlined_probe_value(inner).known()
504 {
505 // known_ty may contain other variables that are known by now
506 tv_stack.push(inner);
507 let result = self.resolve_ty_completely(tv_stack, known_ty.clone());
508 tv_stack.pop();
509 result
510 } else {
511 tv.fallback_value()
512 }
513 }
514 _ => ty,
515 })
516 }
517
518 fn resolve_variant(&mut self, path: Option<&Path>) -> (Ty, Option<VariantDef>) {
519 let path = match path {
520 Some(path) => path,
521 None => return (Ty::Unknown, None),
522 };
523 let resolver = &self.resolver;
524 let def: TypableDef =
525 // FIXME: this should resolve assoc items as well, see this example:
526 // https://play.rust-lang.org/?gist=087992e9e22495446c01c0d4e2d69521
527 match resolver.resolve_path_in_type_ns_fully(self.db, &path) {
528 Some(TypeNs::AdtId(AdtId::StructId(it))) => it.into(),
529 Some(TypeNs::AdtId(AdtId::UnionId(it))) => it.into(),
530 Some(TypeNs::AdtSelfType(adt)) => adt.into(),
531 Some(TypeNs::EnumVariantId(it)) => it.into(),
532 Some(TypeNs::TypeAliasId(it)) => it.into(),
533
534 Some(TypeNs::SelfType(_)) |
535 Some(TypeNs::GenericParam(_)) |
536 Some(TypeNs::BuiltinType(_)) |
537 Some(TypeNs::TraitId(_)) |
538 Some(TypeNs::AdtId(AdtId::EnumId(_))) |
539 None => {
540 return (Ty::Unknown, None)
541 }
542 };
543 // FIXME remove the duplication between here and `Ty::from_path`?
544 let substs = Ty::substs_from_path(self.db, resolver, path, def);
545 match def {
546 TypableDef::Adt(Adt::Struct(s)) => {
547 let ty = s.ty(self.db);
548 let ty = self.insert_type_vars(ty.apply_substs(substs));
549 (ty, Some(s.into()))
550 }
551 TypableDef::EnumVariant(var) => {
552 let ty = var.parent_enum(self.db).ty(self.db);
553 let ty = self.insert_type_vars(ty.apply_substs(substs));
554 (ty, Some(var.into()))
555 }
556 TypableDef::Adt(Adt::Enum(_))
557 | TypableDef::Adt(Adt::Union(_))
558 | TypableDef::TypeAlias(_)
559 | TypableDef::Function(_)
560 | TypableDef::Const(_)
561 | TypableDef::Static(_)
562 | TypableDef::BuiltinType(_) => (Ty::Unknown, None),
563 }
564 }
565
566 fn collect_const(&mut self, data: &ConstData) {
567 self.return_ty = self.make_ty(&data.type_ref);
568 }
569
570 fn collect_fn(&mut self, data: &FunctionData) {
571 let body = Arc::clone(&self.body); // avoid borrow checker problem
572 for (type_ref, pat) in data.params.iter().zip(body.params.iter()) {
573 let ty = self.make_ty(type_ref);
574
575 self.infer_pat(*pat, &ty, BindingMode::default());
576 }
577 self.return_ty = self.make_ty(&data.ret_type);
578 }
579
580 fn infer_body(&mut self) {
581 self.infer_expr(self.body.body_expr, &Expectation::has_type(self.return_ty.clone()));
582 }
583
584 fn resolve_into_iter_item(&self) -> Option<TypeAlias> {
585 let path = known::std_iter_into_iterator();
586 let trait_: Trait = self.resolver.resolve_known_trait(self.db, &path)?.into();
587 trait_.associated_type_by_name(self.db, &name::ITEM_TYPE)
588 }
589
590 fn resolve_ops_try_ok(&self) -> Option<TypeAlias> {
591 let path = known::std_ops_try();
592 let trait_: Trait = self.resolver.resolve_known_trait(self.db, &path)?.into();
593 trait_.associated_type_by_name(self.db, &name::OK_TYPE)
594 }
595
596 fn resolve_future_future_output(&self) -> Option<TypeAlias> {
597 let path = known::std_future_future();
598 let trait_: Trait = self.resolver.resolve_known_trait(self.db, &path)?.into();
599 trait_.associated_type_by_name(self.db, &name::OUTPUT_TYPE)
600 }
601
602 fn resolve_boxed_box(&self) -> Option<Adt> {
603 let path = known::std_boxed_box();
604 let struct_ = self.resolver.resolve_known_struct(self.db, &path)?;
605 Some(Adt::Struct(struct_.into()))
606 }
607}
608
609/// The ID of a type variable.
610#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
611pub struct TypeVarId(pub(super) u32);
612
613impl UnifyKey for TypeVarId {
614 type Value = TypeVarValue;
615
616 fn index(&self) -> u32 {
617 self.0
618 }
619
620 fn from_index(i: u32) -> Self {
621 TypeVarId(i)
622 }
623
624 fn tag() -> &'static str {
625 "TypeVarId"
626 }
627}
628
629/// The value of a type variable: either we already know the type, or we don't
630/// know it yet.
631#[derive(Clone, PartialEq, Eq, Debug)]
632pub enum TypeVarValue {
633 Known(Ty),
634 Unknown,
635}
636
637impl TypeVarValue {
638 fn known(&self) -> Option<&Ty> {
639 match self {
640 TypeVarValue::Known(ty) => Some(ty),
641 TypeVarValue::Unknown => None,
642 }
643 }
644}
645
646impl UnifyValue for TypeVarValue {
647 type Error = NoError;
648
649 fn unify_values(value1: &Self, value2: &Self) -> Result<Self, NoError> {
650 match (value1, value2) {
651 // We should never equate two type variables, both of which have
652 // known types. Instead, we recursively equate those types.
653 (TypeVarValue::Known(t1), TypeVarValue::Known(t2)) => panic!(
654 "equating two type variables, both of which have known types: {:?} and {:?}",
655 t1, t2
656 ),
657
658 // If one side is known, prefer that one.
659 (TypeVarValue::Known(..), TypeVarValue::Unknown) => Ok(value1.clone()),
660 (TypeVarValue::Unknown, TypeVarValue::Known(..)) => Ok(value2.clone()),
661
662 (TypeVarValue::Unknown, TypeVarValue::Unknown) => Ok(TypeVarValue::Unknown),
663 }
664 }
665}
666
667/// The kinds of placeholders we need during type inference. There's separate
668/// values for general types, and for integer and float variables. The latter
669/// two are used for inference of literal values (e.g. `100` could be one of
670/// several integer types).
671#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
672pub enum InferTy {
673 TypeVar(TypeVarId),
674 IntVar(TypeVarId),
675 FloatVar(TypeVarId),
676 MaybeNeverTypeVar(TypeVarId),
677}
678
679impl InferTy {
680 fn to_inner(self) -> TypeVarId {
681 match self {
682 InferTy::TypeVar(ty)
683 | InferTy::IntVar(ty)
684 | InferTy::FloatVar(ty)
685 | InferTy::MaybeNeverTypeVar(ty) => ty,
686 }
687 }
688
689 fn fallback_value(self) -> Ty {
690 match self {
691 InferTy::TypeVar(..) => Ty::Unknown,
692 InferTy::IntVar(..) => Ty::simple(TypeCtor::Int(Uncertain::Known(IntTy::i32()))),
693 InferTy::FloatVar(..) => Ty::simple(TypeCtor::Float(Uncertain::Known(FloatTy::f64()))),
694 InferTy::MaybeNeverTypeVar(..) => Ty::simple(TypeCtor::Never),
695 }
696 }
697}
698
699/// When inferring an expression, we propagate downward whatever type hint we
700/// are able in the form of an `Expectation`.
701#[derive(Clone, PartialEq, Eq, Debug)]
702struct Expectation {
703 ty: Ty,
704 // FIXME: In some cases, we need to be aware whether the expectation is that
705 // the type match exactly what we passed, or whether it just needs to be
706 // coercible to the expected type. See Expectation::rvalue_hint in rustc.
707}
708
709impl Expectation {
710 /// The expectation that the type of the expression needs to equal the given
711 /// type.
712 fn has_type(ty: Ty) -> Self {
713 Expectation { ty }
714 }
715
716 /// This expresses no expectation on the type.
717 fn none() -> Self {
718 Expectation { ty: Ty::Unknown }
719 }
720}
721
722mod diagnostics {
723 use hir_expand::diagnostics::DiagnosticSink;
724
725 use crate::{db::HirDatabase, diagnostics::NoSuchField, expr::ExprId, Function, HasSource};
726
727 #[derive(Debug, PartialEq, Eq, Clone)]
728 pub(super) enum InferenceDiagnostic {
729 NoSuchField { expr: ExprId, field: usize },
730 }
731
732 impl InferenceDiagnostic {
733 pub(super) fn add_to(
734 &self,
735 db: &impl HirDatabase,
736 owner: Function,
737 sink: &mut DiagnosticSink,
738 ) {
739 match self {
740 InferenceDiagnostic::NoSuchField { expr, field } => {
741 let file = owner.source(db).file_id;
742 let field = owner.body_source_map(db).field_syntax(*expr, *field);
743 sink.push(NoSuchField { file, field })
744 }
745 }
746 }
747 }
748}
diff --git a/crates/ra_hir/src/ty/infer/coerce.rs b/crates/ra_hir/src/ty/infer/coerce.rs
deleted file mode 100644
index 54765da35..000000000
--- a/crates/ra_hir/src/ty/infer/coerce.rs
+++ /dev/null
@@ -1,339 +0,0 @@
1//! Coercion logic. Coercions are certain type conversions that can implicitly
2//! happen in certain places, e.g. weakening `&mut` to `&` or deref coercions
3//! like going from `&Vec<T>` to `&[T]`.
4//!
5//! See: https://doc.rust-lang.org/nomicon/coercions.html
6
7use hir_def::{lang_item::LangItemTarget, resolver::Resolver};
8use rustc_hash::FxHashMap;
9use test_utils::tested_by;
10
11use crate::{
12 db::HirDatabase,
13 ty::{autoderef, Substs, Ty, TypeCtor, TypeWalk},
14 Adt, Mutability,
15};
16
17use super::{InferTy, InferenceContext, TypeVarValue};
18
19impl<'a, D: HirDatabase> InferenceContext<'a, D> {
20 /// Unify two types, but may coerce the first one to the second one
21 /// using "implicit coercion rules" if needed.
22 pub(super) fn coerce(&mut self, from_ty: &Ty, to_ty: &Ty) -> bool {
23 let from_ty = self.resolve_ty_shallow(from_ty).into_owned();
24 let to_ty = self.resolve_ty_shallow(to_ty);
25 self.coerce_inner(from_ty, &to_ty)
26 }
27
28 /// Merge two types from different branches, with possible implicit coerce.
29 ///
30 /// Note that it is only possible that one type are coerced to another.
31 /// Coercing both types to another least upper bound type is not possible in rustc,
32 /// which will simply result in "incompatible types" error.
33 pub(super) fn coerce_merge_branch<'t>(&mut self, ty1: &Ty, ty2: &Ty) -> Ty {
34 if self.coerce(ty1, ty2) {
35 ty2.clone()
36 } else if self.coerce(ty2, ty1) {
37 ty1.clone()
38 } else {
39 tested_by!(coerce_merge_fail_fallback);
40 // For incompatible types, we use the latter one as result
41 // to be better recovery for `if` without `else`.
42 ty2.clone()
43 }
44 }
45
46 pub(super) fn init_coerce_unsized_map(
47 db: &'a D,
48 resolver: &Resolver,
49 ) -> FxHashMap<(TypeCtor, TypeCtor), usize> {
50 let krate = resolver.krate().unwrap();
51 let impls = match db.lang_item(krate.into(), "coerce_unsized".into()) {
52 Some(LangItemTarget::TraitId(trait_)) => {
53 db.impls_for_trait(krate.into(), trait_.into())
54 }
55 _ => return FxHashMap::default(),
56 };
57
58 impls
59 .iter()
60 .filter_map(|impl_block| {
61 // `CoerseUnsized` has one generic parameter for the target type.
62 let trait_ref = impl_block.target_trait_ref(db)?;
63 let cur_from_ty = trait_ref.substs.0.get(0)?;
64 let cur_to_ty = trait_ref.substs.0.get(1)?;
65
66 match (&cur_from_ty, cur_to_ty) {
67 (ty_app!(ctor1, st1), ty_app!(ctor2, st2)) => {
68 // FIXME: We return the first non-equal bound as the type parameter to coerce to unsized type.
69 // This works for smart-pointer-like coercion, which covers all impls from std.
70 st1.iter().zip(st2.iter()).enumerate().find_map(|(i, (ty1, ty2))| {
71 match (ty1, ty2) {
72 (Ty::Param { idx: p1, .. }, Ty::Param { idx: p2, .. })
73 if p1 != p2 =>
74 {
75 Some(((*ctor1, *ctor2), i))
76 }
77 _ => None,
78 }
79 })
80 }
81 _ => None,
82 }
83 })
84 .collect()
85 }
86
87 fn coerce_inner(&mut self, mut from_ty: Ty, to_ty: &Ty) -> bool {
88 match (&from_ty, to_ty) {
89 // Never type will make type variable to fallback to Never Type instead of Unknown.
90 (ty_app!(TypeCtor::Never), Ty::Infer(InferTy::TypeVar(tv))) => {
91 let var = self.new_maybe_never_type_var();
92 self.var_unification_table.union_value(*tv, TypeVarValue::Known(var));
93 return true;
94 }
95 (ty_app!(TypeCtor::Never), _) => return true,
96
97 // Trivial cases, this should go after `never` check to
98 // avoid infer result type to be never
99 _ => {
100 if self.unify_inner_trivial(&from_ty, &to_ty) {
101 return true;
102 }
103 }
104 }
105
106 // Pointer weakening and function to pointer
107 match (&mut from_ty, to_ty) {
108 // `*mut T`, `&mut T, `&T`` -> `*const T`
109 // `&mut T` -> `&T`
110 // `&mut T` -> `*mut T`
111 (ty_app!(c1@TypeCtor::RawPtr(_)), ty_app!(c2@TypeCtor::RawPtr(Mutability::Shared)))
112 | (ty_app!(c1@TypeCtor::Ref(_)), ty_app!(c2@TypeCtor::RawPtr(Mutability::Shared)))
113 | (ty_app!(c1@TypeCtor::Ref(_)), ty_app!(c2@TypeCtor::Ref(Mutability::Shared)))
114 | (ty_app!(c1@TypeCtor::Ref(Mutability::Mut)), ty_app!(c2@TypeCtor::RawPtr(_))) => {
115 *c1 = *c2;
116 }
117
118 // Illegal mutablity conversion
119 (
120 ty_app!(TypeCtor::RawPtr(Mutability::Shared)),
121 ty_app!(TypeCtor::RawPtr(Mutability::Mut)),
122 )
123 | (
124 ty_app!(TypeCtor::Ref(Mutability::Shared)),
125 ty_app!(TypeCtor::Ref(Mutability::Mut)),
126 ) => return false,
127
128 // `{function_type}` -> `fn()`
129 (ty_app!(TypeCtor::FnDef(_)), ty_app!(TypeCtor::FnPtr { .. })) => {
130 match from_ty.callable_sig(self.db) {
131 None => return false,
132 Some(sig) => {
133 let num_args = sig.params_and_return.len() as u16 - 1;
134 from_ty =
135 Ty::apply(TypeCtor::FnPtr { num_args }, Substs(sig.params_and_return));
136 }
137 }
138 }
139
140 _ => {}
141 }
142
143 if let Some(ret) = self.try_coerce_unsized(&from_ty, &to_ty) {
144 return ret;
145 }
146
147 // Auto Deref if cannot coerce
148 match (&from_ty, to_ty) {
149 // FIXME: DerefMut
150 (ty_app!(TypeCtor::Ref(_), st1), ty_app!(TypeCtor::Ref(_), st2)) => {
151 self.unify_autoderef_behind_ref(&st1[0], &st2[0])
152 }
153
154 // Otherwise, normal unify
155 _ => self.unify(&from_ty, to_ty),
156 }
157 }
158
159 /// Coerce a type using `from_ty: CoerceUnsized<ty_ty>`
160 ///
161 /// See: https://doc.rust-lang.org/nightly/std/marker/trait.CoerceUnsized.html
162 fn try_coerce_unsized(&mut self, from_ty: &Ty, to_ty: &Ty) -> Option<bool> {
163 let (ctor1, st1, ctor2, st2) = match (from_ty, to_ty) {
164 (ty_app!(ctor1, st1), ty_app!(ctor2, st2)) => (ctor1, st1, ctor2, st2),
165 _ => return None,
166 };
167
168 let coerce_generic_index = *self.coerce_unsized_map.get(&(*ctor1, *ctor2))?;
169
170 // Check `Unsize` first
171 match self.check_unsize_and_coerce(
172 st1.0.get(coerce_generic_index)?,
173 st2.0.get(coerce_generic_index)?,
174 0,
175 ) {
176 Some(true) => {}
177 ret => return ret,
178 }
179
180 let ret = st1
181 .iter()
182 .zip(st2.iter())
183 .enumerate()
184 .filter(|&(idx, _)| idx != coerce_generic_index)
185 .all(|(_, (ty1, ty2))| self.unify(ty1, ty2));
186
187 Some(ret)
188 }
189
190 /// Check if `from_ty: Unsize<to_ty>`, and coerce to `to_ty` if it holds.
191 ///
192 /// It should not be directly called. It is only used by `try_coerce_unsized`.
193 ///
194 /// See: https://doc.rust-lang.org/nightly/std/marker/trait.Unsize.html
195 fn check_unsize_and_coerce(&mut self, from_ty: &Ty, to_ty: &Ty, depth: usize) -> Option<bool> {
196 if depth > 1000 {
197 panic!("Infinite recursion in coercion");
198 }
199
200 match (&from_ty, &to_ty) {
201 // `[T; N]` -> `[T]`
202 (ty_app!(TypeCtor::Array, st1), ty_app!(TypeCtor::Slice, st2)) => {
203 Some(self.unify(&st1[0], &st2[0]))
204 }
205
206 // `T` -> `dyn Trait` when `T: Trait`
207 (_, Ty::Dyn(_)) => {
208 // FIXME: Check predicates
209 Some(true)
210 }
211
212 // `(..., T)` -> `(..., U)` when `T: Unsize<U>`
213 (
214 ty_app!(TypeCtor::Tuple { cardinality: len1 }, st1),
215 ty_app!(TypeCtor::Tuple { cardinality: len2 }, st2),
216 ) => {
217 if len1 != len2 || *len1 == 0 {
218 return None;
219 }
220
221 match self.check_unsize_and_coerce(
222 st1.last().unwrap(),
223 st2.last().unwrap(),
224 depth + 1,
225 ) {
226 Some(true) => {}
227 ret => return ret,
228 }
229
230 let ret = st1[..st1.len() - 1]
231 .iter()
232 .zip(&st2[..st2.len() - 1])
233 .all(|(ty1, ty2)| self.unify(ty1, ty2));
234
235 Some(ret)
236 }
237
238 // Foo<..., T, ...> is Unsize<Foo<..., U, ...>> if:
239 // - T: Unsize<U>
240 // - Foo is a struct
241 // - Only the last field of Foo has a type involving T
242 // - T is not part of the type of any other fields
243 // - Bar<T>: Unsize<Bar<U>>, if the last field of Foo has type Bar<T>
244 (
245 ty_app!(TypeCtor::Adt(Adt::Struct(struct1)), st1),
246 ty_app!(TypeCtor::Adt(Adt::Struct(struct2)), st2),
247 ) if struct1 == struct2 => {
248 let field_tys = self.db.field_types(struct1.id.into());
249 let struct_data = self.db.struct_data(struct1.id.0);
250
251 let mut fields = struct_data.variant_data.fields().iter();
252 let (last_field_id, _data) = fields.next_back()?;
253
254 // Get the generic parameter involved in the last field.
255 let unsize_generic_index = {
256 let mut index = None;
257 let mut multiple_param = false;
258 field_tys[last_field_id].walk(&mut |ty| match ty {
259 &Ty::Param { idx, .. } => {
260 if index.is_none() {
261 index = Some(idx);
262 } else if Some(idx) != index {
263 multiple_param = true;
264 }
265 }
266 _ => {}
267 });
268
269 if multiple_param {
270 return None;
271 }
272 index?
273 };
274
275 // Check other fields do not involve it.
276 let mut multiple_used = false;
277 fields.for_each(|(field_id, _data)| {
278 field_tys[field_id].walk(&mut |ty| match ty {
279 &Ty::Param { idx, .. } if idx == unsize_generic_index => {
280 multiple_used = true
281 }
282 _ => {}
283 })
284 });
285 if multiple_used {
286 return None;
287 }
288
289 let unsize_generic_index = unsize_generic_index as usize;
290
291 // Check `Unsize` first
292 match self.check_unsize_and_coerce(
293 st1.get(unsize_generic_index)?,
294 st2.get(unsize_generic_index)?,
295 depth + 1,
296 ) {
297 Some(true) => {}
298 ret => return ret,
299 }
300
301 // Then unify other parameters
302 let ret = st1
303 .iter()
304 .zip(st2.iter())
305 .enumerate()
306 .filter(|&(idx, _)| idx != unsize_generic_index)
307 .all(|(_, (ty1, ty2))| self.unify(ty1, ty2));
308
309 Some(ret)
310 }
311
312 _ => None,
313 }
314 }
315
316 /// Unify `from_ty` to `to_ty` with optional auto Deref
317 ///
318 /// Note that the parameters are already stripped the outer reference.
319 fn unify_autoderef_behind_ref(&mut self, from_ty: &Ty, to_ty: &Ty) -> bool {
320 let canonicalized = self.canonicalizer().canonicalize_ty(from_ty.clone());
321 let to_ty = self.resolve_ty_shallow(&to_ty);
322 // FIXME: Auto DerefMut
323 for derefed_ty in
324 autoderef::autoderef(self.db, &self.resolver.clone(), canonicalized.value.clone())
325 {
326 let derefed_ty = canonicalized.decanonicalize_ty(derefed_ty.value);
327 match (&*self.resolve_ty_shallow(&derefed_ty), &*to_ty) {
328 // Stop when constructor matches.
329 (ty_app!(from_ctor, st1), ty_app!(to_ctor, st2)) if from_ctor == to_ctor => {
330 // It will not recurse to `coerce`.
331 return self.unify_substs(st1, st2, 0);
332 }
333 _ => {}
334 }
335 }
336
337 false
338 }
339}
diff --git a/crates/ra_hir/src/ty/infer/expr.rs b/crates/ra_hir/src/ty/infer/expr.rs
deleted file mode 100644
index 663ff9435..000000000
--- a/crates/ra_hir/src/ty/infer/expr.rs
+++ /dev/null
@@ -1,667 +0,0 @@
1//! Type inference for expressions.
2
3use std::iter::{repeat, repeat_with};
4use std::sync::Arc;
5
6use hir_def::{
7 builtin_type::Signedness,
8 generics::GenericParams,
9 path::{GenericArg, GenericArgs},
10 resolver::resolver_for_expr,
11};
12use hir_expand::name;
13
14use crate::{
15 db::HirDatabase,
16 expr::{Array, BinaryOp, Expr, ExprId, Literal, Statement, UnaryOp},
17 ty::{
18 autoderef, method_resolution, op, CallableDef, InferTy, IntTy, Mutability, Namespace,
19 Obligation, ProjectionPredicate, ProjectionTy, Substs, TraitRef, Ty, TypeCtor, TypeWalk,
20 Uncertain,
21 },
22 Adt, Name,
23};
24
25use super::{BindingMode, Expectation, InferenceContext, InferenceDiagnostic, TypeMismatch};
26
27impl<'a, D: HirDatabase> InferenceContext<'a, D> {
28 pub(super) fn infer_expr(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty {
29 let ty = self.infer_expr_inner(tgt_expr, expected);
30 let could_unify = self.unify(&ty, &expected.ty);
31 if !could_unify {
32 self.result.type_mismatches.insert(
33 tgt_expr,
34 TypeMismatch { expected: expected.ty.clone(), actual: ty.clone() },
35 );
36 }
37 let ty = self.resolve_ty_as_possible(&mut vec![], ty);
38 ty
39 }
40
41 /// Infer type of expression with possibly implicit coerce to the expected type.
42 /// Return the type after possible coercion.
43 fn infer_expr_coerce(&mut self, expr: ExprId, expected: &Expectation) -> Ty {
44 let ty = self.infer_expr_inner(expr, &expected);
45 let ty = if !self.coerce(&ty, &expected.ty) {
46 self.result
47 .type_mismatches
48 .insert(expr, TypeMismatch { expected: expected.ty.clone(), actual: ty.clone() });
49 // Return actual type when type mismatch.
50 // This is needed for diagnostic when return type mismatch.
51 ty
52 } else if expected.ty == Ty::Unknown {
53 ty
54 } else {
55 expected.ty.clone()
56 };
57
58 self.resolve_ty_as_possible(&mut vec![], ty)
59 }
60
61 fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty {
62 let body = Arc::clone(&self.body); // avoid borrow checker problem
63 let ty = match &body[tgt_expr] {
64 Expr::Missing => Ty::Unknown,
65 Expr::If { condition, then_branch, else_branch } => {
66 // if let is desugared to match, so this is always simple if
67 self.infer_expr(*condition, &Expectation::has_type(Ty::simple(TypeCtor::Bool)));
68
69 let then_ty = self.infer_expr_inner(*then_branch, &expected);
70 let else_ty = match else_branch {
71 Some(else_branch) => self.infer_expr_inner(*else_branch, &expected),
72 None => Ty::unit(),
73 };
74
75 self.coerce_merge_branch(&then_ty, &else_ty)
76 }
77 Expr::Block { statements, tail } => self.infer_block(statements, *tail, expected),
78 Expr::TryBlock { body } => {
79 let _inner = self.infer_expr(*body, expected);
80 // FIXME should be std::result::Result<{inner}, _>
81 Ty::Unknown
82 }
83 Expr::Loop { body } => {
84 self.infer_expr(*body, &Expectation::has_type(Ty::unit()));
85 // FIXME handle break with value
86 Ty::simple(TypeCtor::Never)
87 }
88 Expr::While { condition, body } => {
89 // while let is desugared to a match loop, so this is always simple while
90 self.infer_expr(*condition, &Expectation::has_type(Ty::simple(TypeCtor::Bool)));
91 self.infer_expr(*body, &Expectation::has_type(Ty::unit()));
92 Ty::unit()
93 }
94 Expr::For { iterable, body, pat } => {
95 let iterable_ty = self.infer_expr(*iterable, &Expectation::none());
96
97 let pat_ty = match self.resolve_into_iter_item() {
98 Some(into_iter_item_alias) => {
99 let pat_ty = self.new_type_var();
100 let projection = ProjectionPredicate {
101 ty: pat_ty.clone(),
102 projection_ty: ProjectionTy {
103 associated_ty: into_iter_item_alias,
104 parameters: Substs::single(iterable_ty),
105 },
106 };
107 self.obligations.push(Obligation::Projection(projection));
108 self.resolve_ty_as_possible(&mut vec![], pat_ty)
109 }
110 None => Ty::Unknown,
111 };
112
113 self.infer_pat(*pat, &pat_ty, BindingMode::default());
114 self.infer_expr(*body, &Expectation::has_type(Ty::unit()));
115 Ty::unit()
116 }
117 Expr::Lambda { body, args, arg_types } => {
118 assert_eq!(args.len(), arg_types.len());
119
120 let mut sig_tys = Vec::new();
121
122 for (arg_pat, arg_type) in args.iter().zip(arg_types.iter()) {
123 let expected = if let Some(type_ref) = arg_type {
124 self.make_ty(type_ref)
125 } else {
126 Ty::Unknown
127 };
128 let arg_ty = self.infer_pat(*arg_pat, &expected, BindingMode::default());
129 sig_tys.push(arg_ty);
130 }
131
132 // add return type
133 let ret_ty = self.new_type_var();
134 sig_tys.push(ret_ty.clone());
135 let sig_ty = Ty::apply(
136 TypeCtor::FnPtr { num_args: sig_tys.len() as u16 - 1 },
137 Substs(sig_tys.into()),
138 );
139 let closure_ty =
140 Ty::apply_one(TypeCtor::Closure { def: self.owner, expr: tgt_expr }, sig_ty);
141
142 // Eagerly try to relate the closure type with the expected
143 // type, otherwise we often won't have enough information to
144 // infer the body.
145 self.coerce(&closure_ty, &expected.ty);
146
147 self.infer_expr(*body, &Expectation::has_type(ret_ty));
148 closure_ty
149 }
150 Expr::Call { callee, args } => {
151 let callee_ty = self.infer_expr(*callee, &Expectation::none());
152 let (param_tys, ret_ty) = match callee_ty.callable_sig(self.db) {
153 Some(sig) => (sig.params().to_vec(), sig.ret().clone()),
154 None => {
155 // Not callable
156 // FIXME: report an error
157 (Vec::new(), Ty::Unknown)
158 }
159 };
160 self.register_obligations_for_call(&callee_ty);
161 self.check_call_arguments(args, &param_tys);
162 let ret_ty = self.normalize_associated_types_in(ret_ty);
163 ret_ty
164 }
165 Expr::MethodCall { receiver, args, method_name, generic_args } => self
166 .infer_method_call(tgt_expr, *receiver, &args, &method_name, generic_args.as_ref()),
167 Expr::Match { expr, arms } => {
168 let input_ty = self.infer_expr(*expr, &Expectation::none());
169
170 let mut result_ty = self.new_maybe_never_type_var();
171
172 for arm in arms {
173 for &pat in &arm.pats {
174 let _pat_ty = self.infer_pat(pat, &input_ty, BindingMode::default());
175 }
176 if let Some(guard_expr) = arm.guard {
177 self.infer_expr(
178 guard_expr,
179 &Expectation::has_type(Ty::simple(TypeCtor::Bool)),
180 );
181 }
182
183 let arm_ty = self.infer_expr_inner(arm.expr, &expected);
184 result_ty = self.coerce_merge_branch(&result_ty, &arm_ty);
185 }
186
187 result_ty
188 }
189 Expr::Path(p) => {
190 // FIXME this could be more efficient...
191 let resolver = resolver_for_expr(self.db, self.owner.into(), tgt_expr);
192 self.infer_path(&resolver, p, tgt_expr.into()).unwrap_or(Ty::Unknown)
193 }
194 Expr::Continue => Ty::simple(TypeCtor::Never),
195 Expr::Break { expr } => {
196 if let Some(expr) = expr {
197 // FIXME handle break with value
198 self.infer_expr(*expr, &Expectation::none());
199 }
200 Ty::simple(TypeCtor::Never)
201 }
202 Expr::Return { expr } => {
203 if let Some(expr) = expr {
204 self.infer_expr(*expr, &Expectation::has_type(self.return_ty.clone()));
205 }
206 Ty::simple(TypeCtor::Never)
207 }
208 Expr::RecordLit { path, fields, spread } => {
209 let (ty, def_id) = self.resolve_variant(path.as_ref());
210 if let Some(variant) = def_id {
211 self.write_variant_resolution(tgt_expr.into(), variant);
212 }
213
214 self.unify(&ty, &expected.ty);
215
216 let substs = ty.substs().unwrap_or_else(Substs::empty);
217 let field_types =
218 def_id.map(|it| self.db.field_types(it.into())).unwrap_or_default();
219 for (field_idx, field) in fields.iter().enumerate() {
220 let field_def = def_id.and_then(|it| match it.field(self.db, &field.name) {
221 Some(field) => Some(field),
222 None => {
223 self.push_diagnostic(InferenceDiagnostic::NoSuchField {
224 expr: tgt_expr,
225 field: field_idx,
226 });
227 None
228 }
229 });
230 if let Some(field_def) = field_def {
231 self.result.record_field_resolutions.insert(field.expr, field_def);
232 }
233 let field_ty = field_def
234 .map_or(Ty::Unknown, |it| field_types[it.id].clone())
235 .subst(&substs);
236 self.infer_expr_coerce(field.expr, &Expectation::has_type(field_ty));
237 }
238 if let Some(expr) = spread {
239 self.infer_expr(*expr, &Expectation::has_type(ty.clone()));
240 }
241 ty
242 }
243 Expr::Field { expr, name } => {
244 let receiver_ty = self.infer_expr(*expr, &Expectation::none());
245 let canonicalized = self.canonicalizer().canonicalize_ty(receiver_ty);
246 let ty = autoderef::autoderef(
247 self.db,
248 &self.resolver.clone(),
249 canonicalized.value.clone(),
250 )
251 .find_map(|derefed_ty| match canonicalized.decanonicalize_ty(derefed_ty.value) {
252 Ty::Apply(a_ty) => match a_ty.ctor {
253 TypeCtor::Tuple { .. } => name
254 .as_tuple_index()
255 .and_then(|idx| a_ty.parameters.0.get(idx).cloned()),
256 TypeCtor::Adt(Adt::Struct(s)) => s.field(self.db, name).map(|field| {
257 self.write_field_resolution(tgt_expr, field);
258 self.db.field_types(s.id.into())[field.id]
259 .clone()
260 .subst(&a_ty.parameters)
261 }),
262 _ => None,
263 },
264 _ => None,
265 })
266 .unwrap_or(Ty::Unknown);
267 let ty = self.insert_type_vars(ty);
268 self.normalize_associated_types_in(ty)
269 }
270 Expr::Await { expr } => {
271 let inner_ty = self.infer_expr(*expr, &Expectation::none());
272 let ty = match self.resolve_future_future_output() {
273 Some(future_future_output_alias) => {
274 let ty = self.new_type_var();
275 let projection = ProjectionPredicate {
276 ty: ty.clone(),
277 projection_ty: ProjectionTy {
278 associated_ty: future_future_output_alias,
279 parameters: Substs::single(inner_ty),
280 },
281 };
282 self.obligations.push(Obligation::Projection(projection));
283 self.resolve_ty_as_possible(&mut vec![], ty)
284 }
285 None => Ty::Unknown,
286 };
287 ty
288 }
289 Expr::Try { expr } => {
290 let inner_ty = self.infer_expr(*expr, &Expectation::none());
291 let ty = match self.resolve_ops_try_ok() {
292 Some(ops_try_ok_alias) => {
293 let ty = self.new_type_var();
294 let projection = ProjectionPredicate {
295 ty: ty.clone(),
296 projection_ty: ProjectionTy {
297 associated_ty: ops_try_ok_alias,
298 parameters: Substs::single(inner_ty),
299 },
300 };
301 self.obligations.push(Obligation::Projection(projection));
302 self.resolve_ty_as_possible(&mut vec![], ty)
303 }
304 None => Ty::Unknown,
305 };
306 ty
307 }
308 Expr::Cast { expr, type_ref } => {
309 let _inner_ty = self.infer_expr(*expr, &Expectation::none());
310 let cast_ty = self.make_ty(type_ref);
311 // FIXME check the cast...
312 cast_ty
313 }
314 Expr::Ref { expr, mutability } => {
315 let expectation =
316 if let Some((exp_inner, exp_mutability)) = &expected.ty.as_reference() {
317 if *exp_mutability == Mutability::Mut && *mutability == Mutability::Shared {
318 // FIXME: throw type error - expected mut reference but found shared ref,
319 // which cannot be coerced
320 }
321 Expectation::has_type(Ty::clone(exp_inner))
322 } else {
323 Expectation::none()
324 };
325 // FIXME reference coercions etc.
326 let inner_ty = self.infer_expr(*expr, &expectation);
327 Ty::apply_one(TypeCtor::Ref(*mutability), inner_ty)
328 }
329 Expr::Box { expr } => {
330 let inner_ty = self.infer_expr(*expr, &Expectation::none());
331 if let Some(box_) = self.resolve_boxed_box() {
332 Ty::apply_one(TypeCtor::Adt(box_), inner_ty)
333 } else {
334 Ty::Unknown
335 }
336 }
337 Expr::UnaryOp { expr, op } => {
338 let inner_ty = self.infer_expr(*expr, &Expectation::none());
339 match op {
340 UnaryOp::Deref => {
341 let canonicalized = self.canonicalizer().canonicalize_ty(inner_ty);
342 if let Some(derefed_ty) =
343 autoderef::deref(self.db, &self.resolver, &canonicalized.value)
344 {
345 canonicalized.decanonicalize_ty(derefed_ty.value)
346 } else {
347 Ty::Unknown
348 }
349 }
350 UnaryOp::Neg => {
351 match &inner_ty {
352 Ty::Apply(a_ty) => match a_ty.ctor {
353 TypeCtor::Int(Uncertain::Unknown)
354 | TypeCtor::Int(Uncertain::Known(IntTy {
355 signedness: Signedness::Signed,
356 ..
357 }))
358 | TypeCtor::Float(..) => inner_ty,
359 _ => Ty::Unknown,
360 },
361 Ty::Infer(InferTy::IntVar(..)) | Ty::Infer(InferTy::FloatVar(..)) => {
362 inner_ty
363 }
364 // FIXME: resolve ops::Neg trait
365 _ => Ty::Unknown,
366 }
367 }
368 UnaryOp::Not => {
369 match &inner_ty {
370 Ty::Apply(a_ty) => match a_ty.ctor {
371 TypeCtor::Bool | TypeCtor::Int(_) => inner_ty,
372 _ => Ty::Unknown,
373 },
374 Ty::Infer(InferTy::IntVar(..)) => inner_ty,
375 // FIXME: resolve ops::Not trait for inner_ty
376 _ => Ty::Unknown,
377 }
378 }
379 }
380 }
381 Expr::BinaryOp { lhs, rhs, op } => match op {
382 Some(op) => {
383 let lhs_expectation = match op {
384 BinaryOp::LogicOp(..) => Expectation::has_type(Ty::simple(TypeCtor::Bool)),
385 _ => Expectation::none(),
386 };
387 let lhs_ty = self.infer_expr(*lhs, &lhs_expectation);
388 // FIXME: find implementation of trait corresponding to operation
389 // symbol and resolve associated `Output` type
390 let rhs_expectation = op::binary_op_rhs_expectation(*op, lhs_ty);
391 let rhs_ty = self.infer_expr(*rhs, &Expectation::has_type(rhs_expectation));
392
393 // FIXME: similar as above, return ty is often associated trait type
394 op::binary_op_return_ty(*op, rhs_ty)
395 }
396 _ => Ty::Unknown,
397 },
398 Expr::Index { base, index } => {
399 let _base_ty = self.infer_expr(*base, &Expectation::none());
400 let _index_ty = self.infer_expr(*index, &Expectation::none());
401 // FIXME: use `std::ops::Index::Output` to figure out the real return type
402 Ty::Unknown
403 }
404 Expr::Tuple { exprs } => {
405 let mut tys = match &expected.ty {
406 ty_app!(TypeCtor::Tuple { .. }, st) => st
407 .iter()
408 .cloned()
409 .chain(repeat_with(|| self.new_type_var()))
410 .take(exprs.len())
411 .collect::<Vec<_>>(),
412 _ => (0..exprs.len()).map(|_| self.new_type_var()).collect(),
413 };
414
415 for (expr, ty) in exprs.iter().zip(tys.iter_mut()) {
416 self.infer_expr_coerce(*expr, &Expectation::has_type(ty.clone()));
417 }
418
419 Ty::apply(TypeCtor::Tuple { cardinality: tys.len() as u16 }, Substs(tys.into()))
420 }
421 Expr::Array(array) => {
422 let elem_ty = match &expected.ty {
423 ty_app!(TypeCtor::Array, st) | ty_app!(TypeCtor::Slice, st) => {
424 st.as_single().clone()
425 }
426 _ => self.new_type_var(),
427 };
428
429 match array {
430 Array::ElementList(items) => {
431 for expr in items.iter() {
432 self.infer_expr_coerce(*expr, &Expectation::has_type(elem_ty.clone()));
433 }
434 }
435 Array::Repeat { initializer, repeat } => {
436 self.infer_expr_coerce(
437 *initializer,
438 &Expectation::has_type(elem_ty.clone()),
439 );
440 self.infer_expr(
441 *repeat,
442 &Expectation::has_type(Ty::simple(TypeCtor::Int(Uncertain::Known(
443 IntTy::usize(),
444 )))),
445 );
446 }
447 }
448
449 Ty::apply_one(TypeCtor::Array, elem_ty)
450 }
451 Expr::Literal(lit) => match lit {
452 Literal::Bool(..) => Ty::simple(TypeCtor::Bool),
453 Literal::String(..) => {
454 Ty::apply_one(TypeCtor::Ref(Mutability::Shared), Ty::simple(TypeCtor::Str))
455 }
456 Literal::ByteString(..) => {
457 let byte_type = Ty::simple(TypeCtor::Int(Uncertain::Known(IntTy::u8())));
458 let slice_type = Ty::apply_one(TypeCtor::Slice, byte_type);
459 Ty::apply_one(TypeCtor::Ref(Mutability::Shared), slice_type)
460 }
461 Literal::Char(..) => Ty::simple(TypeCtor::Char),
462 Literal::Int(_v, ty) => Ty::simple(TypeCtor::Int((*ty).into())),
463 Literal::Float(_v, ty) => Ty::simple(TypeCtor::Float((*ty).into())),
464 },
465 };
466 // use a new type variable if we got Ty::Unknown here
467 let ty = self.insert_type_vars_shallow(ty);
468 let ty = self.resolve_ty_as_possible(&mut vec![], ty);
469 self.write_expr_ty(tgt_expr, ty.clone());
470 ty
471 }
472
473 fn infer_block(
474 &mut self,
475 statements: &[Statement],
476 tail: Option<ExprId>,
477 expected: &Expectation,
478 ) -> Ty {
479 let mut diverges = false;
480 for stmt in statements {
481 match stmt {
482 Statement::Let { pat, type_ref, initializer } => {
483 let decl_ty =
484 type_ref.as_ref().map(|tr| self.make_ty(tr)).unwrap_or(Ty::Unknown);
485
486 // Always use the declared type when specified
487 let mut ty = decl_ty.clone();
488
489 if let Some(expr) = initializer {
490 let actual_ty =
491 self.infer_expr_coerce(*expr, &Expectation::has_type(decl_ty.clone()));
492 if decl_ty == Ty::Unknown {
493 ty = actual_ty;
494 }
495 }
496
497 let ty = self.resolve_ty_as_possible(&mut vec![], ty);
498 self.infer_pat(*pat, &ty, BindingMode::default());
499 }
500 Statement::Expr(expr) => {
501 if let ty_app!(TypeCtor::Never) = self.infer_expr(*expr, &Expectation::none()) {
502 diverges = true;
503 }
504 }
505 }
506 }
507
508 let ty = if let Some(expr) = tail {
509 self.infer_expr_coerce(expr, expected)
510 } else {
511 self.coerce(&Ty::unit(), &expected.ty);
512 Ty::unit()
513 };
514 if diverges {
515 Ty::simple(TypeCtor::Never)
516 } else {
517 ty
518 }
519 }
520
521 fn infer_method_call(
522 &mut self,
523 tgt_expr: ExprId,
524 receiver: ExprId,
525 args: &[ExprId],
526 method_name: &Name,
527 generic_args: Option<&GenericArgs>,
528 ) -> Ty {
529 let receiver_ty = self.infer_expr(receiver, &Expectation::none());
530 let canonicalized_receiver = self.canonicalizer().canonicalize_ty(receiver_ty.clone());
531 let resolved = method_resolution::lookup_method(
532 &canonicalized_receiver.value,
533 self.db,
534 method_name,
535 &self.resolver,
536 );
537 let (derefed_receiver_ty, method_ty, def_generics) = match resolved {
538 Some((ty, func)) => {
539 let ty = canonicalized_receiver.decanonicalize_ty(ty);
540 self.write_method_resolution(tgt_expr, func);
541 (
542 ty,
543 self.db.type_for_def(func.into(), Namespace::Values),
544 Some(self.db.generic_params(func.id.into())),
545 )
546 }
547 None => (receiver_ty, Ty::Unknown, None),
548 };
549 let substs = self.substs_for_method_call(def_generics, generic_args, &derefed_receiver_ty);
550 let method_ty = method_ty.apply_substs(substs);
551 let method_ty = self.insert_type_vars(method_ty);
552 self.register_obligations_for_call(&method_ty);
553 let (expected_receiver_ty, param_tys, ret_ty) = match method_ty.callable_sig(self.db) {
554 Some(sig) => {
555 if !sig.params().is_empty() {
556 (sig.params()[0].clone(), sig.params()[1..].to_vec(), sig.ret().clone())
557 } else {
558 (Ty::Unknown, Vec::new(), sig.ret().clone())
559 }
560 }
561 None => (Ty::Unknown, Vec::new(), Ty::Unknown),
562 };
563 // Apply autoref so the below unification works correctly
564 // FIXME: return correct autorefs from lookup_method
565 let actual_receiver_ty = match expected_receiver_ty.as_reference() {
566 Some((_, mutability)) => Ty::apply_one(TypeCtor::Ref(mutability), derefed_receiver_ty),
567 _ => derefed_receiver_ty,
568 };
569 self.unify(&expected_receiver_ty, &actual_receiver_ty);
570
571 self.check_call_arguments(args, &param_tys);
572 let ret_ty = self.normalize_associated_types_in(ret_ty);
573 ret_ty
574 }
575
576 fn check_call_arguments(&mut self, args: &[ExprId], param_tys: &[Ty]) {
577 // Quoting https://github.com/rust-lang/rust/blob/6ef275e6c3cb1384ec78128eceeb4963ff788dca/src/librustc_typeck/check/mod.rs#L3325 --
578 // We do this in a pretty awful way: first we type-check any arguments
579 // that are not closures, then we type-check the closures. This is so
580 // that we have more information about the types of arguments when we
581 // type-check the functions. This isn't really the right way to do this.
582 for &check_closures in &[false, true] {
583 let param_iter = param_tys.iter().cloned().chain(repeat(Ty::Unknown));
584 for (&arg, param_ty) in args.iter().zip(param_iter) {
585 let is_closure = match &self.body[arg] {
586 Expr::Lambda { .. } => true,
587 _ => false,
588 };
589
590 if is_closure != check_closures {
591 continue;
592 }
593
594 let param_ty = self.normalize_associated_types_in(param_ty);
595 self.infer_expr_coerce(arg, &Expectation::has_type(param_ty.clone()));
596 }
597 }
598 }
599
600 fn substs_for_method_call(
601 &mut self,
602 def_generics: Option<Arc<GenericParams>>,
603 generic_args: Option<&GenericArgs>,
604 receiver_ty: &Ty,
605 ) -> Substs {
606 let (parent_param_count, param_count) =
607 def_generics.as_ref().map_or((0, 0), |g| (g.count_parent_params(), g.params.len()));
608 let mut substs = Vec::with_capacity(parent_param_count + param_count);
609 // Parent arguments are unknown, except for the receiver type
610 if let Some(parent_generics) = def_generics.and_then(|p| p.parent_params.clone()) {
611 for param in &parent_generics.params {
612 if param.name == name::SELF_TYPE {
613 substs.push(receiver_ty.clone());
614 } else {
615 substs.push(Ty::Unknown);
616 }
617 }
618 }
619 // handle provided type arguments
620 if let Some(generic_args) = generic_args {
621 // if args are provided, it should be all of them, but we can't rely on that
622 for arg in generic_args.args.iter().take(param_count) {
623 match arg {
624 GenericArg::Type(type_ref) => {
625 let ty = self.make_ty(type_ref);
626 substs.push(ty);
627 }
628 }
629 }
630 };
631 let supplied_params = substs.len();
632 for _ in supplied_params..parent_param_count + param_count {
633 substs.push(Ty::Unknown);
634 }
635 assert_eq!(substs.len(), parent_param_count + param_count);
636 Substs(substs.into())
637 }
638
639 fn register_obligations_for_call(&mut self, callable_ty: &Ty) {
640 if let Ty::Apply(a_ty) = callable_ty {
641 if let TypeCtor::FnDef(def) = a_ty.ctor {
642 let generic_predicates = self.db.generic_predicates(def.into());
643 for predicate in generic_predicates.iter() {
644 let predicate = predicate.clone().subst(&a_ty.parameters);
645 if let Some(obligation) = Obligation::from_predicate(predicate) {
646 self.obligations.push(obligation);
647 }
648 }
649 // add obligation for trait implementation, if this is a trait method
650 match def {
651 CallableDef::Function(f) => {
652 if let Some(trait_) = f.parent_trait(self.db) {
653 // construct a TraitDef
654 let substs = a_ty.parameters.prefix(
655 self.db
656 .generic_params(trait_.id.into())
657 .count_params_including_parent(),
658 );
659 self.obligations.push(Obligation::Trait(TraitRef { trait_, substs }));
660 }
661 }
662 CallableDef::Struct(_) | CallableDef::EnumVariant(_) => {}
663 }
664 }
665 }
666 }
667}
diff --git a/crates/ra_hir/src/ty/infer/pat.rs b/crates/ra_hir/src/ty/infer/pat.rs
deleted file mode 100644
index 641d61e87..000000000
--- a/crates/ra_hir/src/ty/infer/pat.rs
+++ /dev/null
@@ -1,183 +0,0 @@
1//! Type inference for patterns.
2
3use std::iter::repeat;
4use std::sync::Arc;
5
6use test_utils::tested_by;
7
8use super::{BindingMode, InferenceContext};
9use crate::{
10 db::HirDatabase,
11 expr::{BindingAnnotation, Pat, PatId, RecordFieldPat},
12 ty::{Mutability, Substs, Ty, TypeCtor, TypeWalk},
13 Name, Path,
14};
15
16impl<'a, D: HirDatabase> InferenceContext<'a, D> {
17 fn infer_tuple_struct_pat(
18 &mut self,
19 path: Option<&Path>,
20 subpats: &[PatId],
21 expected: &Ty,
22 default_bm: BindingMode,
23 ) -> Ty {
24 let (ty, def) = self.resolve_variant(path);
25
26 self.unify(&ty, expected);
27
28 let substs = ty.substs().unwrap_or_else(Substs::empty);
29
30 let field_tys = def.map(|it| self.db.field_types(it.into())).unwrap_or_default();
31 for (i, &subpat) in subpats.iter().enumerate() {
32 let expected_ty = def
33 .and_then(|d| d.field(self.db, &Name::new_tuple_field(i)))
34 .map_or(Ty::Unknown, |field| field_tys[field.id].clone())
35 .subst(&substs);
36 let expected_ty = self.normalize_associated_types_in(expected_ty);
37 self.infer_pat(subpat, &expected_ty, default_bm);
38 }
39
40 ty
41 }
42
43 fn infer_record_pat(
44 &mut self,
45 path: Option<&Path>,
46 subpats: &[RecordFieldPat],
47 expected: &Ty,
48 default_bm: BindingMode,
49 id: PatId,
50 ) -> Ty {
51 let (ty, def) = self.resolve_variant(path);
52 if let Some(variant) = def {
53 self.write_variant_resolution(id.into(), variant);
54 }
55
56 self.unify(&ty, expected);
57
58 let substs = ty.substs().unwrap_or_else(Substs::empty);
59
60 let field_tys = def.map(|it| self.db.field_types(it.into())).unwrap_or_default();
61 for subpat in subpats {
62 let matching_field = def.and_then(|it| it.field(self.db, &subpat.name));
63 let expected_ty = matching_field
64 .map_or(Ty::Unknown, |field| field_tys[field.id].clone())
65 .subst(&substs);
66 let expected_ty = self.normalize_associated_types_in(expected_ty);
67 self.infer_pat(subpat.pat, &expected_ty, default_bm);
68 }
69
70 ty
71 }
72
73 pub(super) fn infer_pat(
74 &mut self,
75 pat: PatId,
76 mut expected: &Ty,
77 mut default_bm: BindingMode,
78 ) -> Ty {
79 let body = Arc::clone(&self.body); // avoid borrow checker problem
80
81 let is_non_ref_pat = match &body[pat] {
82 Pat::Tuple(..)
83 | Pat::TupleStruct { .. }
84 | Pat::Record { .. }
85 | Pat::Range { .. }
86 | Pat::Slice { .. } => true,
87 // FIXME: Path/Lit might actually evaluate to ref, but inference is unimplemented.
88 Pat::Path(..) | Pat::Lit(..) => true,
89 Pat::Wild | Pat::Bind { .. } | Pat::Ref { .. } | Pat::Missing => false,
90 };
91 if is_non_ref_pat {
92 while let Some((inner, mutability)) = expected.as_reference() {
93 expected = inner;
94 default_bm = match default_bm {
95 BindingMode::Move => BindingMode::Ref(mutability),
96 BindingMode::Ref(Mutability::Shared) => BindingMode::Ref(Mutability::Shared),
97 BindingMode::Ref(Mutability::Mut) => BindingMode::Ref(mutability),
98 }
99 }
100 } else if let Pat::Ref { .. } = &body[pat] {
101 tested_by!(match_ergonomics_ref);
102 // When you encounter a `&pat` pattern, reset to Move.
103 // This is so that `w` is by value: `let (_, &w) = &(1, &2);`
104 default_bm = BindingMode::Move;
105 }
106
107 // Lose mutability.
108 let default_bm = default_bm;
109 let expected = expected;
110
111 let ty = match &body[pat] {
112 Pat::Tuple(ref args) => {
113 let expectations = match expected.as_tuple() {
114 Some(parameters) => &*parameters.0,
115 _ => &[],
116 };
117 let expectations_iter = expectations.iter().chain(repeat(&Ty::Unknown));
118
119 let inner_tys = args
120 .iter()
121 .zip(expectations_iter)
122 .map(|(&pat, ty)| self.infer_pat(pat, ty, default_bm))
123 .collect();
124
125 Ty::apply(TypeCtor::Tuple { cardinality: args.len() as u16 }, Substs(inner_tys))
126 }
127 Pat::Ref { pat, mutability } => {
128 let expectation = match expected.as_reference() {
129 Some((inner_ty, exp_mut)) => {
130 if *mutability != exp_mut {
131 // FIXME: emit type error?
132 }
133 inner_ty
134 }
135 _ => &Ty::Unknown,
136 };
137 let subty = self.infer_pat(*pat, expectation, default_bm);
138 Ty::apply_one(TypeCtor::Ref(*mutability), subty)
139 }
140 Pat::TupleStruct { path: p, args: subpats } => {
141 self.infer_tuple_struct_pat(p.as_ref(), subpats, expected, default_bm)
142 }
143 Pat::Record { path: p, args: fields } => {
144 self.infer_record_pat(p.as_ref(), fields, expected, default_bm, pat)
145 }
146 Pat::Path(path) => {
147 // FIXME use correct resolver for the surrounding expression
148 let resolver = self.resolver.clone();
149 self.infer_path(&resolver, &path, pat.into()).unwrap_or(Ty::Unknown)
150 }
151 Pat::Bind { mode, name: _, subpat } => {
152 let mode = if mode == &BindingAnnotation::Unannotated {
153 default_bm
154 } else {
155 BindingMode::convert(*mode)
156 };
157 let inner_ty = if let Some(subpat) = subpat {
158 self.infer_pat(*subpat, expected, default_bm)
159 } else {
160 expected.clone()
161 };
162 let inner_ty = self.insert_type_vars_shallow(inner_ty);
163
164 let bound_ty = match mode {
165 BindingMode::Ref(mutability) => {
166 Ty::apply_one(TypeCtor::Ref(mutability), inner_ty.clone())
167 }
168 BindingMode::Move => inner_ty.clone(),
169 };
170 let bound_ty = self.resolve_ty_as_possible(&mut vec![], bound_ty);
171 self.write_pat_ty(pat, bound_ty);
172 return inner_ty;
173 }
174 _ => Ty::Unknown,
175 };
176 // use a new type variable if we got Ty::Unknown here
177 let ty = self.insert_type_vars_shallow(ty);
178 self.unify(&ty, expected);
179 let ty = self.resolve_ty_as_possible(&mut vec![], ty);
180 self.write_pat_ty(pat, ty.clone());
181 ty
182 }
183}
diff --git a/crates/ra_hir/src/ty/infer/path.rs b/crates/ra_hir/src/ty/infer/path.rs
deleted file mode 100644
index ee54d8217..000000000
--- a/crates/ra_hir/src/ty/infer/path.rs
+++ /dev/null
@@ -1,258 +0,0 @@
1//! Path expression resolution.
2
3use hir_def::{
4 path::PathSegment,
5 resolver::{ResolveValueResult, Resolver, TypeNs, ValueNs},
6};
7
8use crate::{
9 db::HirDatabase,
10 ty::{method_resolution, Namespace, Substs, Ty, TypableDef, TypeWalk},
11 AssocItem, Container, Function, Name, Path,
12};
13
14use super::{ExprOrPatId, InferenceContext, TraitRef};
15
16impl<'a, D: HirDatabase> InferenceContext<'a, D> {
17 pub(super) fn infer_path(
18 &mut self,
19 resolver: &Resolver,
20 path: &Path,
21 id: ExprOrPatId,
22 ) -> Option<Ty> {
23 let ty = self.resolve_value_path(resolver, path, id)?;
24 let ty = self.insert_type_vars(ty);
25 let ty = self.normalize_associated_types_in(ty);
26 Some(ty)
27 }
28
29 fn resolve_value_path(
30 &mut self,
31 resolver: &Resolver,
32 path: &Path,
33 id: ExprOrPatId,
34 ) -> Option<Ty> {
35 let (value, self_subst) = if let crate::PathKind::Type(type_ref) = &path.kind {
36 if path.segments.is_empty() {
37 // This can't actually happen syntax-wise
38 return None;
39 }
40 let ty = self.make_ty(type_ref);
41 let remaining_segments_for_ty = &path.segments[..path.segments.len() - 1];
42 let ty = Ty::from_type_relative_path(self.db, resolver, ty, remaining_segments_for_ty);
43 self.resolve_ty_assoc_item(
44 ty,
45 &path.segments.last().expect("path had at least one segment").name,
46 id,
47 )?
48 } else {
49 let value_or_partial = resolver.resolve_path_in_value_ns(self.db, &path)?;
50
51 match value_or_partial {
52 ResolveValueResult::ValueNs(it) => (it, None),
53 ResolveValueResult::Partial(def, remaining_index) => {
54 self.resolve_assoc_item(def, path, remaining_index, id)?
55 }
56 }
57 };
58
59 let typable: TypableDef = match value {
60 ValueNs::LocalBinding(pat) => {
61 let ty = self.result.type_of_pat.get(pat)?.clone();
62 let ty = self.resolve_ty_as_possible(&mut vec![], ty);
63 return Some(ty);
64 }
65 ValueNs::FunctionId(it) => it.into(),
66 ValueNs::ConstId(it) => it.into(),
67 ValueNs::StaticId(it) => it.into(),
68 ValueNs::StructId(it) => it.into(),
69 ValueNs::EnumVariantId(it) => it.into(),
70 };
71
72 let mut ty = self.db.type_for_def(typable, Namespace::Values);
73 if let Some(self_subst) = self_subst {
74 ty = ty.subst(&self_subst);
75 }
76
77 let substs = Ty::substs_from_path(self.db, &self.resolver, path, typable);
78 let ty = ty.subst(&substs);
79 Some(ty)
80 }
81
82 fn resolve_assoc_item(
83 &mut self,
84 def: TypeNs,
85 path: &Path,
86 remaining_index: usize,
87 id: ExprOrPatId,
88 ) -> Option<(ValueNs, Option<Substs>)> {
89 assert!(remaining_index < path.segments.len());
90 // there may be more intermediate segments between the resolved one and
91 // the end. Only the last segment needs to be resolved to a value; from
92 // the segments before that, we need to get either a type or a trait ref.
93
94 let resolved_segment = &path.segments[remaining_index - 1];
95 let remaining_segments = &path.segments[remaining_index..];
96 let is_before_last = remaining_segments.len() == 1;
97
98 match (def, is_before_last) {
99 (TypeNs::TraitId(trait_), true) => {
100 let segment =
101 remaining_segments.last().expect("there should be at least one segment here");
102 let trait_ref = TraitRef::from_resolved_path(
103 self.db,
104 &self.resolver,
105 trait_.into(),
106 resolved_segment,
107 None,
108 );
109 self.resolve_trait_assoc_item(trait_ref, segment, id)
110 }
111 (def, _) => {
112 // Either we already have a type (e.g. `Vec::new`), or we have a
113 // trait but it's not the last segment, so the next segment
114 // should resolve to an associated type of that trait (e.g. `<T
115 // as Iterator>::Item::default`)
116 let remaining_segments_for_ty = &remaining_segments[..remaining_segments.len() - 1];
117 let ty = Ty::from_partly_resolved_hir_path(
118 self.db,
119 &self.resolver,
120 def,
121 resolved_segment,
122 remaining_segments_for_ty,
123 );
124 if let Ty::Unknown = ty {
125 return None;
126 }
127
128 let ty = self.insert_type_vars(ty);
129 let ty = self.normalize_associated_types_in(ty);
130
131 let segment =
132 remaining_segments.last().expect("there should be at least one segment here");
133
134 self.resolve_ty_assoc_item(ty, &segment.name, id)
135 }
136 }
137 }
138
139 fn resolve_trait_assoc_item(
140 &mut self,
141 trait_ref: TraitRef,
142 segment: &PathSegment,
143 id: ExprOrPatId,
144 ) -> Option<(ValueNs, Option<Substs>)> {
145 let trait_ = trait_ref.trait_;
146 let item = trait_.items(self.db).iter().copied().find_map(|item| match item {
147 AssocItem::Function(func) => {
148 if segment.name == func.name(self.db) {
149 Some(AssocItem::Function(func))
150 } else {
151 None
152 }
153 }
154
155 AssocItem::Const(konst) => {
156 if konst.name(self.db).map_or(false, |n| n == segment.name) {
157 Some(AssocItem::Const(konst))
158 } else {
159 None
160 }
161 }
162 AssocItem::TypeAlias(_) => None,
163 })?;
164 let def = match item {
165 AssocItem::Function(f) => ValueNs::FunctionId(f.id),
166 AssocItem::Const(c) => ValueNs::ConstId(c.id),
167 AssocItem::TypeAlias(_) => unreachable!(),
168 };
169 let substs = Substs::build_for_def(self.db, item)
170 .use_parent_substs(&trait_ref.substs)
171 .fill_with_params()
172 .build();
173
174 self.write_assoc_resolution(id, item);
175 Some((def, Some(substs)))
176 }
177
178 fn resolve_ty_assoc_item(
179 &mut self,
180 ty: Ty,
181 name: &Name,
182 id: ExprOrPatId,
183 ) -> Option<(ValueNs, Option<Substs>)> {
184 if let Ty::Unknown = ty {
185 return None;
186 }
187
188 let canonical_ty = self.canonicalizer().canonicalize_ty(ty.clone());
189
190 method_resolution::iterate_method_candidates(
191 &canonical_ty.value,
192 self.db,
193 &self.resolver.clone(),
194 Some(name),
195 method_resolution::LookupMode::Path,
196 move |_ty, item| {
197 let def = match item {
198 AssocItem::Function(f) => ValueNs::FunctionId(f.id),
199 AssocItem::Const(c) => ValueNs::ConstId(c.id),
200 AssocItem::TypeAlias(_) => unreachable!(),
201 };
202 let substs = match item.container(self.db) {
203 Container::ImplBlock(_) => self.find_self_types(&def, ty.clone()),
204 Container::Trait(t) => {
205 // we're picking this method
206 let trait_substs = Substs::build_for_def(self.db, t)
207 .push(ty.clone())
208 .fill(std::iter::repeat_with(|| self.new_type_var()))
209 .build();
210 let substs = Substs::build_for_def(self.db, item)
211 .use_parent_substs(&trait_substs)
212 .fill_with_params()
213 .build();
214 self.obligations.push(super::Obligation::Trait(TraitRef {
215 trait_: t,
216 substs: trait_substs,
217 }));
218 Some(substs)
219 }
220 };
221
222 self.write_assoc_resolution(id, item);
223 Some((def, substs))
224 },
225 )
226 }
227
228 fn find_self_types(&self, def: &ValueNs, actual_def_ty: Ty) -> Option<Substs> {
229 if let ValueNs::FunctionId(func) = def {
230 let func = Function::from(*func);
231 // We only do the infer if parent has generic params
232 let gen = self.db.generic_params(func.id.into());
233 if gen.count_parent_params() == 0 {
234 return None;
235 }
236
237 let impl_block = func.impl_block(self.db)?.target_ty(self.db);
238 let impl_block_substs = impl_block.substs()?;
239 let actual_substs = actual_def_ty.substs()?;
240
241 let mut new_substs = vec![Ty::Unknown; gen.count_parent_params()];
242
243 // The following code *link up* the function actual parma type
244 // and impl_block type param index
245 impl_block_substs.iter().zip(actual_substs.iter()).for_each(|(param, pty)| {
246 if let Ty::Param { idx, .. } = param {
247 if let Some(s) = new_substs.get_mut(*idx as usize) {
248 *s = pty.clone();
249 }
250 }
251 });
252
253 Some(Substs(new_substs.into()))
254 } else {
255 None
256 }
257 }
258}
diff --git a/crates/ra_hir/src/ty/infer/unify.rs b/crates/ra_hir/src/ty/infer/unify.rs
deleted file mode 100644
index 64d9394cf..000000000
--- a/crates/ra_hir/src/ty/infer/unify.rs
+++ /dev/null
@@ -1,164 +0,0 @@
1//! Unification and canonicalization logic.
2
3use super::{InferenceContext, Obligation};
4use crate::db::HirDatabase;
5use crate::ty::{
6 Canonical, InEnvironment, InferTy, ProjectionPredicate, ProjectionTy, Substs, TraitRef, Ty,
7 TypeWalk,
8};
9use crate::util::make_mut_slice;
10
11impl<'a, D: HirDatabase> InferenceContext<'a, D> {
12 pub(super) fn canonicalizer<'b>(&'b mut self) -> Canonicalizer<'a, 'b, D>
13 where
14 'a: 'b,
15 {
16 Canonicalizer { ctx: self, free_vars: Vec::new(), var_stack: Vec::new() }
17 }
18}
19
20pub(super) struct Canonicalizer<'a, 'b, D: HirDatabase>
21where
22 'a: 'b,
23{
24 ctx: &'b mut InferenceContext<'a, D>,
25 free_vars: Vec<InferTy>,
26 /// A stack of type variables that is used to detect recursive types (which
27 /// are an error, but we need to protect against them to avoid stack
28 /// overflows).
29 var_stack: Vec<super::TypeVarId>,
30}
31
32pub(super) struct Canonicalized<T> {
33 pub value: Canonical<T>,
34 free_vars: Vec<InferTy>,
35}
36
37impl<'a, 'b, D: HirDatabase> Canonicalizer<'a, 'b, D>
38where
39 'a: 'b,
40{
41 fn add(&mut self, free_var: InferTy) -> usize {
42 self.free_vars.iter().position(|&v| v == free_var).unwrap_or_else(|| {
43 let next_index = self.free_vars.len();
44 self.free_vars.push(free_var);
45 next_index
46 })
47 }
48
49 fn do_canonicalize_ty(&mut self, ty: Ty) -> Ty {
50 ty.fold(&mut |ty| match ty {
51 Ty::Infer(tv) => {
52 let inner = tv.to_inner();
53 if self.var_stack.contains(&inner) {
54 // recursive type
55 return tv.fallback_value();
56 }
57 if let Some(known_ty) =
58 self.ctx.var_unification_table.inlined_probe_value(inner).known()
59 {
60 self.var_stack.push(inner);
61 let result = self.do_canonicalize_ty(known_ty.clone());
62 self.var_stack.pop();
63 result
64 } else {
65 let root = self.ctx.var_unification_table.find(inner);
66 let free_var = match tv {
67 InferTy::TypeVar(_) => InferTy::TypeVar(root),
68 InferTy::IntVar(_) => InferTy::IntVar(root),
69 InferTy::FloatVar(_) => InferTy::FloatVar(root),
70 InferTy::MaybeNeverTypeVar(_) => InferTy::MaybeNeverTypeVar(root),
71 };
72 let position = self.add(free_var);
73 Ty::Bound(position as u32)
74 }
75 }
76 _ => ty,
77 })
78 }
79
80 fn do_canonicalize_trait_ref(&mut self, mut trait_ref: TraitRef) -> TraitRef {
81 for ty in make_mut_slice(&mut trait_ref.substs.0) {
82 *ty = self.do_canonicalize_ty(ty.clone());
83 }
84 trait_ref
85 }
86
87 fn into_canonicalized<T>(self, result: T) -> Canonicalized<T> {
88 Canonicalized {
89 value: Canonical { value: result, num_vars: self.free_vars.len() },
90 free_vars: self.free_vars,
91 }
92 }
93
94 fn do_canonicalize_projection_ty(&mut self, mut projection_ty: ProjectionTy) -> ProjectionTy {
95 for ty in make_mut_slice(&mut projection_ty.parameters.0) {
96 *ty = self.do_canonicalize_ty(ty.clone());
97 }
98 projection_ty
99 }
100
101 fn do_canonicalize_projection_predicate(
102 &mut self,
103 projection: ProjectionPredicate,
104 ) -> ProjectionPredicate {
105 let ty = self.do_canonicalize_ty(projection.ty);
106 let projection_ty = self.do_canonicalize_projection_ty(projection.projection_ty);
107
108 ProjectionPredicate { ty, projection_ty }
109 }
110
111 // FIXME: add some point, we need to introduce a `Fold` trait that abstracts
112 // over all the things that can be canonicalized (like Chalk and rustc have)
113
114 pub(crate) fn canonicalize_ty(mut self, ty: Ty) -> Canonicalized<Ty> {
115 let result = self.do_canonicalize_ty(ty);
116 self.into_canonicalized(result)
117 }
118
119 pub(crate) fn canonicalize_obligation(
120 mut self,
121 obligation: InEnvironment<Obligation>,
122 ) -> Canonicalized<InEnvironment<Obligation>> {
123 let result = match obligation.value {
124 Obligation::Trait(tr) => Obligation::Trait(self.do_canonicalize_trait_ref(tr)),
125 Obligation::Projection(pr) => {
126 Obligation::Projection(self.do_canonicalize_projection_predicate(pr))
127 }
128 };
129 self.into_canonicalized(InEnvironment {
130 value: result,
131 environment: obligation.environment,
132 })
133 }
134}
135
136impl<T> Canonicalized<T> {
137 pub fn decanonicalize_ty(&self, mut ty: Ty) -> Ty {
138 ty.walk_mut_binders(
139 &mut |ty, binders| match ty {
140 &mut Ty::Bound(idx) => {
141 if idx as usize >= binders && (idx as usize - binders) < self.free_vars.len() {
142 *ty = Ty::Infer(self.free_vars[idx as usize - binders]);
143 }
144 }
145 _ => {}
146 },
147 0,
148 );
149 ty
150 }
151
152 pub fn apply_solution(
153 &self,
154 ctx: &mut InferenceContext<'_, impl HirDatabase>,
155 solution: Canonical<Vec<Ty>>,
156 ) {
157 // the solution may contain new variables, which we need to convert to new inference vars
158 let new_vars = Substs((0..solution.num_vars).map(|_| ctx.new_type_var()).collect());
159 for (i, ty) in solution.value.into_iter().enumerate() {
160 let var = self.free_vars[i];
161 ctx.unify(&Ty::Infer(var), &ty.subst_bound_vars(&new_vars));
162 }
163 }
164}
diff --git a/crates/ra_hir/src/ty/lower.rs b/crates/ra_hir/src/ty/lower.rs
deleted file mode 100644
index a39beb2a0..000000000
--- a/crates/ra_hir/src/ty/lower.rs
+++ /dev/null
@@ -1,831 +0,0 @@
1//! Methods for lowering the HIR to types. There are two main cases here:
2//!
3//! - Lowering a type reference like `&usize` or `Option<foo::bar::Baz>` to a
4//! type: The entry point for this is `Ty::from_hir`.
5//! - Building the type for an item: This happens through the `type_for_def` query.
6//!
7//! This usually involves resolving names, collecting generic arguments etc.
8use std::iter;
9use std::sync::Arc;
10
11use hir_def::{
12 builtin_type::{BuiltinFloat, BuiltinInt, BuiltinType},
13 generics::WherePredicate,
14 path::{GenericArg, PathSegment},
15 resolver::{HasResolver, Resolver, TypeNs},
16 type_ref::{TypeBound, TypeRef},
17 AdtId, GenericDefId, LocalStructFieldId, VariantId,
18};
19use ra_arena::map::ArenaMap;
20
21use super::{
22 FnSig, GenericPredicate, ProjectionPredicate, ProjectionTy, Substs, TraitRef, Ty, TypeCtor,
23 TypeWalk,
24};
25use crate::{
26 db::HirDatabase,
27 ty::{
28 primitive::{FloatTy, IntTy, Uncertain},
29 Adt,
30 },
31 util::make_mut_slice,
32 Const, Enum, EnumVariant, Function, GenericDef, ImplBlock, ModuleDef, Path, Static, Struct,
33 Trait, TypeAlias, Union,
34};
35
36// FIXME: this is only really used in `type_for_def`, which contains a bunch of
37// impossible cases. Perhaps we should recombine `TypeableDef` and `Namespace`
38// into a `AsTypeDef`, `AsValueDef` enums?
39#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
40pub enum Namespace {
41 Types,
42 Values,
43 // Note that only type inference uses this enum, and it doesn't care about macros.
44 // Macro,
45}
46
47impl Ty {
48 pub(crate) fn from_hir(db: &impl HirDatabase, resolver: &Resolver, type_ref: &TypeRef) -> Self {
49 match type_ref {
50 TypeRef::Never => Ty::simple(TypeCtor::Never),
51 TypeRef::Tuple(inner) => {
52 let inner_tys: Arc<[Ty]> =
53 inner.iter().map(|tr| Ty::from_hir(db, resolver, tr)).collect();
54 Ty::apply(
55 TypeCtor::Tuple { cardinality: inner_tys.len() as u16 },
56 Substs(inner_tys),
57 )
58 }
59 TypeRef::Path(path) => Ty::from_hir_path(db, resolver, path),
60 TypeRef::RawPtr(inner, mutability) => {
61 let inner_ty = Ty::from_hir(db, resolver, inner);
62 Ty::apply_one(TypeCtor::RawPtr(*mutability), inner_ty)
63 }
64 TypeRef::Array(inner) => {
65 let inner_ty = Ty::from_hir(db, resolver, inner);
66 Ty::apply_one(TypeCtor::Array, inner_ty)
67 }
68 TypeRef::Slice(inner) => {
69 let inner_ty = Ty::from_hir(db, resolver, inner);
70 Ty::apply_one(TypeCtor::Slice, inner_ty)
71 }
72 TypeRef::Reference(inner, mutability) => {
73 let inner_ty = Ty::from_hir(db, resolver, inner);
74 Ty::apply_one(TypeCtor::Ref(*mutability), inner_ty)
75 }
76 TypeRef::Placeholder => Ty::Unknown,
77 TypeRef::Fn(params) => {
78 let sig = Substs(params.iter().map(|tr| Ty::from_hir(db, resolver, tr)).collect());
79 Ty::apply(TypeCtor::FnPtr { num_args: sig.len() as u16 - 1 }, sig)
80 }
81 TypeRef::DynTrait(bounds) => {
82 let self_ty = Ty::Bound(0);
83 let predicates = bounds
84 .iter()
85 .flat_map(|b| {
86 GenericPredicate::from_type_bound(db, resolver, b, self_ty.clone())
87 })
88 .collect();
89 Ty::Dyn(predicates)
90 }
91 TypeRef::ImplTrait(bounds) => {
92 let self_ty = Ty::Bound(0);
93 let predicates = bounds
94 .iter()
95 .flat_map(|b| {
96 GenericPredicate::from_type_bound(db, resolver, b, self_ty.clone())
97 })
98 .collect();
99 Ty::Opaque(predicates)
100 }
101 TypeRef::Error => Ty::Unknown,
102 }
103 }
104
105 /// This is only for `generic_predicates_for_param`, where we can't just
106 /// lower the self types of the predicates since that could lead to cycles.
107 /// So we just check here if the `type_ref` resolves to a generic param, and which.
108 fn from_hir_only_param(
109 db: &impl HirDatabase,
110 resolver: &Resolver,
111 type_ref: &TypeRef,
112 ) -> Option<u32> {
113 let path = match type_ref {
114 TypeRef::Path(path) => path,
115 _ => return None,
116 };
117 if let crate::PathKind::Type(_) = &path.kind {
118 return None;
119 }
120 if path.segments.len() > 1 {
121 return None;
122 }
123 let resolution = match resolver.resolve_path_in_type_ns(db, path) {
124 Some((it, None)) => it,
125 _ => return None,
126 };
127 if let TypeNs::GenericParam(idx) = resolution {
128 Some(idx)
129 } else {
130 None
131 }
132 }
133
134 pub(crate) fn from_type_relative_path(
135 db: &impl HirDatabase,
136 resolver: &Resolver,
137 ty: Ty,
138 remaining_segments: &[PathSegment],
139 ) -> Ty {
140 if remaining_segments.len() == 1 {
141 // resolve unselected assoc types
142 let segment = &remaining_segments[0];
143 Ty::select_associated_type(db, resolver, ty, segment)
144 } else if remaining_segments.len() > 1 {
145 // FIXME report error (ambiguous associated type)
146 Ty::Unknown
147 } else {
148 ty
149 }
150 }
151
152 pub(crate) fn from_partly_resolved_hir_path(
153 db: &impl HirDatabase,
154 resolver: &Resolver,
155 resolution: TypeNs,
156 resolved_segment: &PathSegment,
157 remaining_segments: &[PathSegment],
158 ) -> Ty {
159 let ty = match resolution {
160 TypeNs::TraitId(trait_) => {
161 let trait_ref = TraitRef::from_resolved_path(
162 db,
163 resolver,
164 trait_.into(),
165 resolved_segment,
166 None,
167 );
168 return if remaining_segments.len() == 1 {
169 let segment = &remaining_segments[0];
170 match trait_ref
171 .trait_
172 .associated_type_by_name_including_super_traits(db, &segment.name)
173 {
174 Some(associated_ty) => {
175 // FIXME handle type parameters on the segment
176 Ty::Projection(ProjectionTy {
177 associated_ty,
178 parameters: trait_ref.substs,
179 })
180 }
181 None => {
182 // FIXME: report error (associated type not found)
183 Ty::Unknown
184 }
185 }
186 } else if remaining_segments.len() > 1 {
187 // FIXME report error (ambiguous associated type)
188 Ty::Unknown
189 } else {
190 Ty::Dyn(Arc::new([GenericPredicate::Implemented(trait_ref)]))
191 };
192 }
193 TypeNs::GenericParam(idx) => {
194 // FIXME: maybe return name in resolution?
195 let name = resolved_segment.name.clone();
196 Ty::Param { idx, name }
197 }
198 TypeNs::SelfType(impl_block) => ImplBlock::from(impl_block).target_ty(db),
199 TypeNs::AdtSelfType(adt) => Adt::from(adt).ty(db),
200
201 TypeNs::AdtId(it) => Ty::from_hir_path_inner(db, resolver, resolved_segment, it.into()),
202 TypeNs::BuiltinType(it) => {
203 Ty::from_hir_path_inner(db, resolver, resolved_segment, it.into())
204 }
205 TypeNs::TypeAliasId(it) => {
206 Ty::from_hir_path_inner(db, resolver, resolved_segment, it.into())
207 }
208 // FIXME: report error
209 TypeNs::EnumVariantId(_) => return Ty::Unknown,
210 };
211
212 Ty::from_type_relative_path(db, resolver, ty, remaining_segments)
213 }
214
215 pub(crate) fn from_hir_path(db: &impl HirDatabase, resolver: &Resolver, path: &Path) -> Ty {
216 // Resolve the path (in type namespace)
217 if let crate::PathKind::Type(type_ref) = &path.kind {
218 let ty = Ty::from_hir(db, resolver, &type_ref);
219 let remaining_segments = &path.segments[..];
220 return Ty::from_type_relative_path(db, resolver, ty, remaining_segments);
221 }
222 let (resolution, remaining_index) = match resolver.resolve_path_in_type_ns(db, path) {
223 Some(it) => it,
224 None => return Ty::Unknown,
225 };
226 let (resolved_segment, remaining_segments) = match remaining_index {
227 None => (
228 path.segments.last().expect("resolved path has at least one element"),
229 &[] as &[PathSegment],
230 ),
231 Some(i) => (&path.segments[i - 1], &path.segments[i..]),
232 };
233 Ty::from_partly_resolved_hir_path(
234 db,
235 resolver,
236 resolution,
237 resolved_segment,
238 remaining_segments,
239 )
240 }
241
242 fn select_associated_type(
243 db: &impl HirDatabase,
244 resolver: &Resolver,
245 self_ty: Ty,
246 segment: &PathSegment,
247 ) -> Ty {
248 let param_idx = match self_ty {
249 Ty::Param { idx, .. } => idx,
250 _ => return Ty::Unknown, // Error: Ambiguous associated type
251 };
252 let def = match resolver.generic_def() {
253 Some(def) => def,
254 None => return Ty::Unknown, // this can't actually happen
255 };
256 let predicates = db.generic_predicates_for_param(def.into(), param_idx);
257 let traits_from_env = predicates.iter().filter_map(|pred| match pred {
258 GenericPredicate::Implemented(tr) if tr.self_ty() == &self_ty => Some(tr.trait_),
259 _ => None,
260 });
261 let traits = traits_from_env.flat_map(|t| t.all_super_traits(db));
262 for t in traits {
263 if let Some(associated_ty) = t.associated_type_by_name(db, &segment.name) {
264 let substs =
265 Substs::build_for_def(db, t).push(self_ty.clone()).fill_with_unknown().build();
266 // FIXME handle type parameters on the segment
267 return Ty::Projection(ProjectionTy { associated_ty, parameters: substs });
268 }
269 }
270 Ty::Unknown
271 }
272
273 fn from_hir_path_inner(
274 db: &impl HirDatabase,
275 resolver: &Resolver,
276 segment: &PathSegment,
277 typable: TypableDef,
278 ) -> Ty {
279 let ty = db.type_for_def(typable, Namespace::Types);
280 let substs = Ty::substs_from_path_segment(db, resolver, segment, typable);
281 ty.subst(&substs)
282 }
283
284 pub(super) fn substs_from_path_segment(
285 db: &impl HirDatabase,
286 resolver: &Resolver,
287 segment: &PathSegment,
288 resolved: TypableDef,
289 ) -> Substs {
290 let def_generic: Option<GenericDef> = match resolved {
291 TypableDef::Function(func) => Some(func.into()),
292 TypableDef::Adt(adt) => Some(adt.into()),
293 TypableDef::EnumVariant(var) => Some(var.parent_enum(db).into()),
294 TypableDef::TypeAlias(t) => Some(t.into()),
295 TypableDef::Const(_) | TypableDef::Static(_) | TypableDef::BuiltinType(_) => None,
296 };
297 substs_from_path_segment(db, resolver, segment, def_generic, false)
298 }
299
300 /// Collect generic arguments from a path into a `Substs`. See also
301 /// `create_substs_for_ast_path` and `def_to_ty` in rustc.
302 pub(super) fn substs_from_path(
303 db: &impl HirDatabase,
304 resolver: &Resolver,
305 path: &Path,
306 resolved: TypableDef,
307 ) -> Substs {
308 let last = path.segments.last().expect("path should have at least one segment");
309 let segment = match resolved {
310 TypableDef::Function(_)
311 | TypableDef::Adt(_)
312 | TypableDef::Const(_)
313 | TypableDef::Static(_)
314 | TypableDef::TypeAlias(_)
315 | TypableDef::BuiltinType(_) => last,
316 TypableDef::EnumVariant(_) => {
317 // the generic args for an enum variant may be either specified
318 // on the segment referring to the enum, or on the segment
319 // referring to the variant. So `Option::<T>::None` and
320 // `Option::None::<T>` are both allowed (though the former is
321 // preferred). See also `def_ids_for_path_segments` in rustc.
322 let len = path.segments.len();
323 let segment = if len >= 2 && path.segments[len - 2].args_and_bindings.is_some() {
324 // Option::<T>::None
325 &path.segments[len - 2]
326 } else {
327 // Option::None::<T>
328 last
329 };
330 segment
331 }
332 };
333 Ty::substs_from_path_segment(db, resolver, segment, resolved)
334 }
335}
336
337pub(super) fn substs_from_path_segment(
338 db: &impl HirDatabase,
339 resolver: &Resolver,
340 segment: &PathSegment,
341 def_generic: Option<GenericDef>,
342 add_self_param: bool,
343) -> Substs {
344 let mut substs = Vec::new();
345 let def_generics = def_generic.map(|def| db.generic_params(def.into()));
346
347 let (parent_param_count, param_count) =
348 def_generics.map_or((0, 0), |g| (g.count_parent_params(), g.params.len()));
349 substs.extend(iter::repeat(Ty::Unknown).take(parent_param_count));
350 if add_self_param {
351 // FIXME this add_self_param argument is kind of a hack: Traits have the
352 // Self type as an implicit first type parameter, but it can't be
353 // actually provided in the type arguments
354 // (well, actually sometimes it can, in the form of type-relative paths: `<Foo as Default>::default()`)
355 substs.push(Ty::Unknown);
356 }
357 if let Some(generic_args) = &segment.args_and_bindings {
358 // if args are provided, it should be all of them, but we can't rely on that
359 let self_param_correction = if add_self_param { 1 } else { 0 };
360 let param_count = param_count - self_param_correction;
361 for arg in generic_args.args.iter().take(param_count) {
362 match arg {
363 GenericArg::Type(type_ref) => {
364 let ty = Ty::from_hir(db, resolver, type_ref);
365 substs.push(ty);
366 }
367 }
368 }
369 }
370 // add placeholders for args that were not provided
371 let supplied_params = substs.len();
372 for _ in supplied_params..parent_param_count + param_count {
373 substs.push(Ty::Unknown);
374 }
375 assert_eq!(substs.len(), parent_param_count + param_count);
376
377 // handle defaults
378 if let Some(def_generic) = def_generic {
379 let default_substs = db.generic_defaults(def_generic);
380 assert_eq!(substs.len(), default_substs.len());
381
382 for (i, default_ty) in default_substs.iter().enumerate() {
383 if substs[i] == Ty::Unknown {
384 substs[i] = default_ty.clone();
385 }
386 }
387 }
388
389 Substs(substs.into())
390}
391
392impl TraitRef {
393 pub(crate) fn from_path(
394 db: &impl HirDatabase,
395 resolver: &Resolver,
396 path: &Path,
397 explicit_self_ty: Option<Ty>,
398 ) -> Option<Self> {
399 let resolved = match resolver.resolve_path_in_type_ns_fully(db, &path)? {
400 TypeNs::TraitId(tr) => tr,
401 _ => return None,
402 };
403 let segment = path.segments.last().expect("path should have at least one segment");
404 Some(TraitRef::from_resolved_path(db, resolver, resolved.into(), segment, explicit_self_ty))
405 }
406
407 pub(super) fn from_resolved_path(
408 db: &impl HirDatabase,
409 resolver: &Resolver,
410 resolved: Trait,
411 segment: &PathSegment,
412 explicit_self_ty: Option<Ty>,
413 ) -> Self {
414 let mut substs = TraitRef::substs_from_path(db, resolver, segment, resolved);
415 if let Some(self_ty) = explicit_self_ty {
416 make_mut_slice(&mut substs.0)[0] = self_ty;
417 }
418 TraitRef { trait_: resolved, substs }
419 }
420
421 pub(crate) fn from_hir(
422 db: &impl HirDatabase,
423 resolver: &Resolver,
424 type_ref: &TypeRef,
425 explicit_self_ty: Option<Ty>,
426 ) -> Option<Self> {
427 let path = match type_ref {
428 TypeRef::Path(path) => path,
429 _ => return None,
430 };
431 TraitRef::from_path(db, resolver, path, explicit_self_ty)
432 }
433
434 fn substs_from_path(
435 db: &impl HirDatabase,
436 resolver: &Resolver,
437 segment: &PathSegment,
438 resolved: Trait,
439 ) -> Substs {
440 let has_self_param =
441 segment.args_and_bindings.as_ref().map(|a| a.has_self_type).unwrap_or(false);
442 substs_from_path_segment(db, resolver, segment, Some(resolved.into()), !has_self_param)
443 }
444
445 pub(crate) fn for_trait(db: &impl HirDatabase, trait_: Trait) -> TraitRef {
446 let substs = Substs::identity(&db.generic_params(trait_.id.into()));
447 TraitRef { trait_, substs }
448 }
449
450 pub(crate) fn from_type_bound(
451 db: &impl HirDatabase,
452 resolver: &Resolver,
453 bound: &TypeBound,
454 self_ty: Ty,
455 ) -> Option<TraitRef> {
456 match bound {
457 TypeBound::Path(path) => TraitRef::from_path(db, resolver, path, Some(self_ty)),
458 TypeBound::Error => None,
459 }
460 }
461}
462
463impl GenericPredicate {
464 pub(crate) fn from_where_predicate<'a>(
465 db: &'a impl HirDatabase,
466 resolver: &'a Resolver,
467 where_predicate: &'a WherePredicate,
468 ) -> impl Iterator<Item = GenericPredicate> + 'a {
469 let self_ty = Ty::from_hir(db, resolver, &where_predicate.type_ref);
470 GenericPredicate::from_type_bound(db, resolver, &where_predicate.bound, self_ty)
471 }
472
473 pub(crate) fn from_type_bound<'a>(
474 db: &'a impl HirDatabase,
475 resolver: &'a Resolver,
476 bound: &'a TypeBound,
477 self_ty: Ty,
478 ) -> impl Iterator<Item = GenericPredicate> + 'a {
479 let trait_ref = TraitRef::from_type_bound(db, &resolver, bound, self_ty);
480 iter::once(trait_ref.clone().map_or(GenericPredicate::Error, GenericPredicate::Implemented))
481 .chain(
482 trait_ref.into_iter().flat_map(move |tr| {
483 assoc_type_bindings_from_type_bound(db, resolver, bound, tr)
484 }),
485 )
486 }
487}
488
489fn assoc_type_bindings_from_type_bound<'a>(
490 db: &'a impl HirDatabase,
491 resolver: &'a Resolver,
492 bound: &'a TypeBound,
493 trait_ref: TraitRef,
494) -> impl Iterator<Item = GenericPredicate> + 'a {
495 let last_segment = match bound {
496 TypeBound::Path(path) => path.segments.last(),
497 TypeBound::Error => None,
498 };
499 last_segment
500 .into_iter()
501 .flat_map(|segment| segment.args_and_bindings.iter())
502 .flat_map(|args_and_bindings| args_and_bindings.bindings.iter())
503 .map(move |(name, type_ref)| {
504 let associated_ty =
505 match trait_ref.trait_.associated_type_by_name_including_super_traits(db, &name) {
506 None => return GenericPredicate::Error,
507 Some(t) => t,
508 };
509 let projection_ty =
510 ProjectionTy { associated_ty, parameters: trait_ref.substs.clone() };
511 let ty = Ty::from_hir(db, resolver, type_ref);
512 let projection_predicate = ProjectionPredicate { projection_ty, ty };
513 GenericPredicate::Projection(projection_predicate)
514 })
515}
516
517/// Build the declared type of an item. This depends on the namespace; e.g. for
518/// `struct Foo(usize)`, we have two types: The type of the struct itself, and
519/// the constructor function `(usize) -> Foo` which lives in the values
520/// namespace.
521pub(crate) fn type_for_def(db: &impl HirDatabase, def: TypableDef, ns: Namespace) -> Ty {
522 match (def, ns) {
523 (TypableDef::Function(f), Namespace::Values) => type_for_fn(db, f),
524 (TypableDef::Adt(Adt::Struct(s)), Namespace::Values) => type_for_struct_constructor(db, s),
525 (TypableDef::Adt(adt), Namespace::Types) => type_for_adt(db, adt),
526 (TypableDef::EnumVariant(v), Namespace::Values) => type_for_enum_variant_constructor(db, v),
527 (TypableDef::TypeAlias(t), Namespace::Types) => type_for_type_alias(db, t),
528 (TypableDef::Const(c), Namespace::Values) => type_for_const(db, c),
529 (TypableDef::Static(c), Namespace::Values) => type_for_static(db, c),
530 (TypableDef::BuiltinType(t), Namespace::Types) => type_for_builtin(t),
531
532 // 'error' cases:
533 (TypableDef::Function(_), Namespace::Types) => Ty::Unknown,
534 (TypableDef::Adt(Adt::Union(_)), Namespace::Values) => Ty::Unknown,
535 (TypableDef::Adt(Adt::Enum(_)), Namespace::Values) => Ty::Unknown,
536 (TypableDef::EnumVariant(_), Namespace::Types) => Ty::Unknown,
537 (TypableDef::TypeAlias(_), Namespace::Values) => Ty::Unknown,
538 (TypableDef::Const(_), Namespace::Types) => Ty::Unknown,
539 (TypableDef::Static(_), Namespace::Types) => Ty::Unknown,
540 (TypableDef::BuiltinType(_), Namespace::Values) => Ty::Unknown,
541 }
542}
543
544/// Build the signature of a callable item (function, struct or enum variant).
545pub(crate) fn callable_item_sig(db: &impl HirDatabase, def: CallableDef) -> FnSig {
546 match def {
547 CallableDef::Function(f) => fn_sig_for_fn(db, f),
548 CallableDef::Struct(s) => fn_sig_for_struct_constructor(db, s),
549 CallableDef::EnumVariant(e) => fn_sig_for_enum_variant_constructor(db, e),
550 }
551}
552
553/// Build the type of all specific fields of a struct or enum variant.
554pub(crate) fn field_types_query(
555 db: &impl HirDatabase,
556 variant_id: VariantId,
557) -> Arc<ArenaMap<LocalStructFieldId, Ty>> {
558 let (resolver, var_data) = match variant_id {
559 VariantId::StructId(it) => (it.resolver(db), db.struct_data(it.0).variant_data.clone()),
560 VariantId::EnumVariantId(it) => (
561 it.parent.resolver(db),
562 db.enum_data(it.parent).variants[it.local_id].variant_data.clone(),
563 ),
564 };
565 let mut res = ArenaMap::default();
566 for (field_id, field_data) in var_data.fields().iter() {
567 res.insert(field_id, Ty::from_hir(db, &resolver, &field_data.type_ref))
568 }
569 Arc::new(res)
570}
571
572/// This query exists only to be used when resolving short-hand associated types
573/// like `T::Item`.
574///
575/// See the analogous query in rustc and its comment:
576/// https://github.com/rust-lang/rust/blob/9150f844e2624eb013ec78ca08c1d416e6644026/src/librustc_typeck/astconv.rs#L46
577/// This is a query mostly to handle cycles somewhat gracefully; e.g. the
578/// following bounds are disallowed: `T: Foo<U::Item>, U: Foo<T::Item>`, but
579/// these are fine: `T: Foo<U::Item>, U: Foo<()>`.
580pub(crate) fn generic_predicates_for_param_query(
581 db: &impl HirDatabase,
582 def: GenericDef,
583 param_idx: u32,
584) -> Arc<[GenericPredicate]> {
585 let resolver = GenericDefId::from(def).resolver(db);
586 resolver
587 .where_predicates_in_scope()
588 // we have to filter out all other predicates *first*, before attempting to lower them
589 .filter(|pred| Ty::from_hir_only_param(db, &resolver, &pred.type_ref) == Some(param_idx))
590 .flat_map(|pred| GenericPredicate::from_where_predicate(db, &resolver, pred))
591 .collect()
592}
593
594pub(crate) fn trait_env(
595 db: &impl HirDatabase,
596 resolver: &Resolver,
597) -> Arc<super::TraitEnvironment> {
598 let predicates = resolver
599 .where_predicates_in_scope()
600 .flat_map(|pred| GenericPredicate::from_where_predicate(db, &resolver, pred))
601 .collect::<Vec<_>>();
602
603 Arc::new(super::TraitEnvironment { predicates })
604}
605
606/// Resolve the where clause(s) of an item with generics.
607pub(crate) fn generic_predicates_query(
608 db: &impl HirDatabase,
609 def: GenericDef,
610) -> Arc<[GenericPredicate]> {
611 let resolver = GenericDefId::from(def).resolver(db);
612 resolver
613 .where_predicates_in_scope()
614 .flat_map(|pred| GenericPredicate::from_where_predicate(db, &resolver, pred))
615 .collect()
616}
617
618/// Resolve the default type params from generics
619pub(crate) fn generic_defaults_query(db: &impl HirDatabase, def: GenericDef) -> Substs {
620 let resolver = GenericDefId::from(def).resolver(db);
621 let generic_params = db.generic_params(def.into());
622
623 let defaults = generic_params
624 .params_including_parent()
625 .into_iter()
626 .map(|p| p.default.as_ref().map_or(Ty::Unknown, |t| Ty::from_hir(db, &resolver, t)))
627 .collect();
628
629 Substs(defaults)
630}
631
632fn fn_sig_for_fn(db: &impl HirDatabase, def: Function) -> FnSig {
633 let data = db.function_data(def.id);
634 let resolver = def.id.resolver(db);
635 let params = data.params.iter().map(|tr| Ty::from_hir(db, &resolver, tr)).collect::<Vec<_>>();
636 let ret = Ty::from_hir(db, &resolver, &data.ret_type);
637 FnSig::from_params_and_return(params, ret)
638}
639
640/// Build the declared type of a function. This should not need to look at the
641/// function body.
642fn type_for_fn(db: &impl HirDatabase, def: Function) -> Ty {
643 let generics = db.generic_params(def.id.into());
644 let substs = Substs::identity(&generics);
645 Ty::apply(TypeCtor::FnDef(def.into()), substs)
646}
647
648/// Build the declared type of a const.
649fn type_for_const(db: &impl HirDatabase, def: Const) -> Ty {
650 let data = db.const_data(def.id);
651 let resolver = def.id.resolver(db);
652
653 Ty::from_hir(db, &resolver, &data.type_ref)
654}
655
656/// Build the declared type of a static.
657fn type_for_static(db: &impl HirDatabase, def: Static) -> Ty {
658 let data = db.static_data(def.id);
659 let resolver = def.id.resolver(db);
660
661 Ty::from_hir(db, &resolver, &data.type_ref)
662}
663
664/// Build the declared type of a static.
665fn type_for_builtin(def: BuiltinType) -> Ty {
666 Ty::simple(match def {
667 BuiltinType::Char => TypeCtor::Char,
668 BuiltinType::Bool => TypeCtor::Bool,
669 BuiltinType::Str => TypeCtor::Str,
670 BuiltinType::Int(t) => TypeCtor::Int(IntTy::from(t).into()),
671 BuiltinType::Float(t) => TypeCtor::Float(FloatTy::from(t).into()),
672 })
673}
674
675impl From<BuiltinInt> for IntTy {
676 fn from(t: BuiltinInt) -> Self {
677 IntTy { signedness: t.signedness, bitness: t.bitness }
678 }
679}
680
681impl From<BuiltinFloat> for FloatTy {
682 fn from(t: BuiltinFloat) -> Self {
683 FloatTy { bitness: t.bitness }
684 }
685}
686
687impl From<Option<BuiltinInt>> for Uncertain<IntTy> {
688 fn from(t: Option<BuiltinInt>) -> Self {
689 match t {
690 None => Uncertain::Unknown,
691 Some(t) => Uncertain::Known(t.into()),
692 }
693 }
694}
695
696impl From<Option<BuiltinFloat>> for Uncertain<FloatTy> {
697 fn from(t: Option<BuiltinFloat>) -> Self {
698 match t {
699 None => Uncertain::Unknown,
700 Some(t) => Uncertain::Known(t.into()),
701 }
702 }
703}
704
705fn fn_sig_for_struct_constructor(db: &impl HirDatabase, def: Struct) -> FnSig {
706 let struct_data = db.struct_data(def.id.into());
707 let fields = struct_data.variant_data.fields();
708 let resolver = def.id.resolver(db);
709 let params = fields
710 .iter()
711 .map(|(_, field)| Ty::from_hir(db, &resolver, &field.type_ref))
712 .collect::<Vec<_>>();
713 let ret = type_for_adt(db, def);
714 FnSig::from_params_and_return(params, ret)
715}
716
717/// Build the type of a tuple struct constructor.
718fn type_for_struct_constructor(db: &impl HirDatabase, def: Struct) -> Ty {
719 let struct_data = db.struct_data(def.id.into());
720 if struct_data.variant_data.is_unit() {
721 return type_for_adt(db, def); // Unit struct
722 }
723 let generics = db.generic_params(def.id.into());
724 let substs = Substs::identity(&generics);
725 Ty::apply(TypeCtor::FnDef(def.into()), substs)
726}
727
728fn fn_sig_for_enum_variant_constructor(db: &impl HirDatabase, def: EnumVariant) -> FnSig {
729 let var_data = def.variant_data(db);
730 let fields = var_data.fields();
731 let resolver = def.parent.id.resolver(db);
732 let params = fields
733 .iter()
734 .map(|(_, field)| Ty::from_hir(db, &resolver, &field.type_ref))
735 .collect::<Vec<_>>();
736 let generics = db.generic_params(def.parent_enum(db).id.into());
737 let substs = Substs::identity(&generics);
738 let ret = type_for_adt(db, def.parent_enum(db)).subst(&substs);
739 FnSig::from_params_and_return(params, ret)
740}
741
742/// Build the type of a tuple enum variant constructor.
743fn type_for_enum_variant_constructor(db: &impl HirDatabase, def: EnumVariant) -> Ty {
744 let var_data = def.variant_data(db);
745 if var_data.is_unit() {
746 return type_for_adt(db, def.parent_enum(db)); // Unit variant
747 }
748 let generics = db.generic_params(def.parent_enum(db).id.into());
749 let substs = Substs::identity(&generics);
750 Ty::apply(TypeCtor::FnDef(def.into()), substs)
751}
752
753fn type_for_adt(db: &impl HirDatabase, adt: impl Into<Adt>) -> Ty {
754 let adt = adt.into();
755 let adt_id: AdtId = adt.into();
756 let generics = db.generic_params(adt_id.into());
757 Ty::apply(TypeCtor::Adt(adt), Substs::identity(&generics))
758}
759
760fn type_for_type_alias(db: &impl HirDatabase, t: TypeAlias) -> Ty {
761 let generics = db.generic_params(t.id.into());
762 let resolver = t.id.resolver(db);
763 let type_ref = t.type_ref(db);
764 let substs = Substs::identity(&generics);
765 let inner = Ty::from_hir(db, &resolver, &type_ref.unwrap_or(TypeRef::Error));
766 inner.subst(&substs)
767}
768
769#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
770pub enum TypableDef {
771 Function(Function),
772 Adt(Adt),
773 EnumVariant(EnumVariant),
774 TypeAlias(TypeAlias),
775 Const(Const),
776 Static(Static),
777 BuiltinType(BuiltinType),
778}
779impl_froms!(
780 TypableDef: Function,
781 Adt(Struct, Enum, Union),
782 EnumVariant,
783 TypeAlias,
784 Const,
785 Static,
786 BuiltinType
787);
788
789impl From<ModuleDef> for Option<TypableDef> {
790 fn from(def: ModuleDef) -> Option<TypableDef> {
791 let res = match def {
792 ModuleDef::Function(f) => f.into(),
793 ModuleDef::Adt(adt) => adt.into(),
794 ModuleDef::EnumVariant(v) => v.into(),
795 ModuleDef::TypeAlias(t) => t.into(),
796 ModuleDef::Const(v) => v.into(),
797 ModuleDef::Static(v) => v.into(),
798 ModuleDef::BuiltinType(t) => t.into(),
799 ModuleDef::Module(_) | ModuleDef::Trait(_) => return None,
800 };
801 Some(res)
802 }
803}
804
805#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
806pub enum CallableDef {
807 Function(Function),
808 Struct(Struct),
809 EnumVariant(EnumVariant),
810}
811impl_froms!(CallableDef: Function, Struct, EnumVariant);
812
813impl CallableDef {
814 pub fn krate(self, db: &impl HirDatabase) -> Option<crate::Crate> {
815 match self {
816 CallableDef::Function(f) => f.krate(db),
817 CallableDef::Struct(s) => s.krate(db),
818 CallableDef::EnumVariant(e) => e.parent_enum(db).krate(db),
819 }
820 }
821}
822
823impl From<CallableDef> for GenericDef {
824 fn from(def: CallableDef) -> GenericDef {
825 match def {
826 CallableDef::Function(f) => f.into(),
827 CallableDef::Struct(s) => s.into(),
828 CallableDef::EnumVariant(e) => e.into(),
829 }
830 }
831}
diff --git a/crates/ra_hir/src/ty/method_resolution.rs b/crates/ra_hir/src/ty/method_resolution.rs
deleted file mode 100644
index caa5f5f74..000000000
--- a/crates/ra_hir/src/ty/method_resolution.rs
+++ /dev/null
@@ -1,375 +0,0 @@
1//! This module is concerned with finding methods that a given type provides.
2//! For details about how this works in rustc, see the method lookup page in the
3//! [rustc guide](https://rust-lang.github.io/rustc-guide/method-lookup.html)
4//! and the corresponding code mostly in librustc_typeck/check/method/probe.rs.
5use std::sync::Arc;
6
7use arrayvec::ArrayVec;
8use hir_def::{lang_item::LangItemTarget, resolver::Resolver, AstItemDef};
9use rustc_hash::FxHashMap;
10
11use crate::{
12 db::HirDatabase,
13 ty::primitive::{FloatBitness, Uncertain},
14 ty::{Ty, TypeCtor},
15 AssocItem, Crate, Function, ImplBlock, Module, Mutability, Name, Trait,
16};
17
18use super::{autoderef, lower, Canonical, InEnvironment, TraitEnvironment, TraitRef};
19
20/// This is used as a key for indexing impls.
21#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
22pub enum TyFingerprint {
23 Apply(TypeCtor),
24}
25
26impl TyFingerprint {
27 /// Creates a TyFingerprint for looking up an impl. Only certain types can
28 /// have impls: if we have some `struct S`, we can have an `impl S`, but not
29 /// `impl &S`. Hence, this will return `None` for reference types and such.
30 fn for_impl(ty: &Ty) -> Option<TyFingerprint> {
31 match ty {
32 Ty::Apply(a_ty) => Some(TyFingerprint::Apply(a_ty.ctor)),
33 _ => None,
34 }
35 }
36}
37
38#[derive(Debug, PartialEq, Eq)]
39pub struct CrateImplBlocks {
40 impls: FxHashMap<TyFingerprint, Vec<ImplBlock>>,
41 impls_by_trait: FxHashMap<Trait, Vec<ImplBlock>>,
42}
43
44impl CrateImplBlocks {
45 pub(crate) fn impls_in_crate_query(
46 db: &impl HirDatabase,
47 krate: Crate,
48 ) -> Arc<CrateImplBlocks> {
49 let mut crate_impl_blocks =
50 CrateImplBlocks { impls: FxHashMap::default(), impls_by_trait: FxHashMap::default() };
51 if let Some(module) = krate.root_module(db) {
52 crate_impl_blocks.collect_recursive(db, module);
53 }
54 Arc::new(crate_impl_blocks)
55 }
56 pub fn lookup_impl_blocks(&self, ty: &Ty) -> impl Iterator<Item = ImplBlock> + '_ {
57 let fingerprint = TyFingerprint::for_impl(ty);
58 fingerprint.and_then(|f| self.impls.get(&f)).into_iter().flatten().copied()
59 }
60
61 pub fn lookup_impl_blocks_for_trait(&self, tr: Trait) -> impl Iterator<Item = ImplBlock> + '_ {
62 self.impls_by_trait.get(&tr).into_iter().flatten().copied()
63 }
64
65 pub fn all_impls<'a>(&'a self) -> impl Iterator<Item = ImplBlock> + 'a {
66 self.impls.values().chain(self.impls_by_trait.values()).flatten().copied()
67 }
68
69 fn collect_recursive(&mut self, db: &impl HirDatabase, module: Module) {
70 for impl_block in module.impl_blocks(db) {
71 let target_ty = impl_block.target_ty(db);
72
73 if impl_block.target_trait(db).is_some() {
74 if let Some(tr) = impl_block.target_trait_ref(db) {
75 self.impls_by_trait.entry(tr.trait_).or_default().push(impl_block);
76 }
77 } else {
78 if let Some(target_ty_fp) = TyFingerprint::for_impl(&target_ty) {
79 self.impls.entry(target_ty_fp).or_default().push(impl_block);
80 }
81 }
82 }
83
84 for child in module.children(db) {
85 self.collect_recursive(db, child);
86 }
87 }
88}
89
90fn def_crates(db: &impl HirDatabase, cur_crate: Crate, ty: &Ty) -> Option<ArrayVec<[Crate; 2]>> {
91 // Types like slice can have inherent impls in several crates, (core and alloc).
92 // The corresponding impls are marked with lang items, so we can use them to find the required crates.
93 macro_rules! lang_item_crate {
94 ($($name:expr),+ $(,)?) => {{
95 let mut v = ArrayVec::<[LangItemTarget; 2]>::new();
96 $(
97 v.extend(db.lang_item(cur_crate.crate_id, $name.into()));
98 )+
99 v
100 }};
101 }
102
103 let lang_item_targets = match ty {
104 Ty::Apply(a_ty) => match a_ty.ctor {
105 TypeCtor::Adt(def_id) => return Some(std::iter::once(def_id.krate(db)?).collect()),
106 TypeCtor::Bool => lang_item_crate!("bool"),
107 TypeCtor::Char => lang_item_crate!("char"),
108 TypeCtor::Float(Uncertain::Known(f)) => match f.bitness {
109 // There are two lang items: one in libcore (fXX) and one in libstd (fXX_runtime)
110 FloatBitness::X32 => lang_item_crate!("f32", "f32_runtime"),
111 FloatBitness::X64 => lang_item_crate!("f64", "f64_runtime"),
112 },
113 TypeCtor::Int(Uncertain::Known(i)) => lang_item_crate!(i.ty_to_string()),
114 TypeCtor::Str => lang_item_crate!("str_alloc", "str"),
115 TypeCtor::Slice => lang_item_crate!("slice_alloc", "slice"),
116 TypeCtor::RawPtr(Mutability::Shared) => lang_item_crate!("const_ptr"),
117 TypeCtor::RawPtr(Mutability::Mut) => lang_item_crate!("mut_ptr"),
118 _ => return None,
119 },
120 _ => return None,
121 };
122 let res = lang_item_targets
123 .into_iter()
124 .filter_map(|it| match it {
125 LangItemTarget::ImplBlockId(it) => Some(it),
126 _ => None,
127 })
128 .map(|it| it.module(db).krate.into())
129 .collect();
130 Some(res)
131}
132
133/// Look up the method with the given name, returning the actual autoderefed
134/// receiver type (but without autoref applied yet).
135pub(crate) fn lookup_method(
136 ty: &Canonical<Ty>,
137 db: &impl HirDatabase,
138 name: &Name,
139 resolver: &Resolver,
140) -> Option<(Ty, Function)> {
141 iterate_method_candidates(ty, db, resolver, Some(name), LookupMode::MethodCall, |ty, f| match f
142 {
143 AssocItem::Function(f) => Some((ty.clone(), f)),
144 _ => None,
145 })
146}
147
148/// Whether we're looking up a dotted method call (like `v.len()`) or a path
149/// (like `Vec::new`).
150#[derive(Copy, Clone, Debug, PartialEq, Eq)]
151pub enum LookupMode {
152 /// Looking up a method call like `v.len()`: We only consider candidates
153 /// that have a `self` parameter, and do autoderef.
154 MethodCall,
155 /// Looking up a path like `Vec::new` or `Vec::default`: We consider all
156 /// candidates including associated constants, but don't do autoderef.
157 Path,
158}
159
160// This would be nicer if it just returned an iterator, but that runs into
161// lifetime problems, because we need to borrow temp `CrateImplBlocks`.
162// FIXME add a context type here?
163pub(crate) fn iterate_method_candidates<T>(
164 ty: &Canonical<Ty>,
165 db: &impl HirDatabase,
166 resolver: &Resolver,
167