]>
Commit | Line | Data |
---|---|---|
1b1a35ee XL |
1 | use super::callee::DeferredCallResolution; |
2 | use super::MaybeInProgressTables; | |
3 | ||
c295e0f8 | 4 | use rustc_data_structures::fx::FxHashSet; |
1b1a35ee XL |
5 | use rustc_hir as hir; |
6 | use rustc_hir::def_id::{DefIdMap, LocalDefId}; | |
7 | use rustc_hir::HirIdMap; | |
8 | use rustc_infer::infer; | |
9 | use rustc_infer::infer::{InferCtxt, InferOk, TyCtxtInferExt}; | |
10 | use rustc_middle::ty::fold::TypeFoldable; | |
94222f64 | 11 | use rustc_middle::ty::{self, Ty, TyCtxt}; |
1b1a35ee XL |
12 | use rustc_span::{self, Span}; |
13 | use rustc_trait_selection::infer::InferCtxtExt as _; | |
136023e0 | 14 | use rustc_trait_selection::traits::{self, ObligationCause, TraitEngine, TraitEngineExt}; |
1b1a35ee XL |
15 | |
16 | use std::cell::RefCell; | |
17 | use std::ops::Deref; | |
18 | ||
19 | /// Closures defined within the function. For example: | |
20 | /// | |
21 | /// fn foo() { | |
22 | /// bar(move|| { ... }) | |
23 | /// } | |
24 | /// | |
25 | /// Here, the function `foo()` and the closure passed to | |
26 | /// `bar()` will each have their own `FnCtxt`, but they will | |
27 | /// share the inherited fields. | |
28 | pub struct Inherited<'a, 'tcx> { | |
29 | pub(super) infcx: InferCtxt<'a, 'tcx>, | |
30 | ||
31 | pub(super) typeck_results: super::MaybeInProgressTables<'a, 'tcx>, | |
32 | ||
33 | pub(super) locals: RefCell<HirIdMap<super::LocalTy<'tcx>>>, | |
34 | ||
35 | pub(super) fulfillment_cx: RefCell<Box<dyn TraitEngine<'tcx>>>, | |
36 | ||
37 | // Some additional `Sized` obligations badly affect type inference. | |
38 | // These obligations are added in a later stage of typeck. | |
39 | pub(super) deferred_sized_obligations: | |
40 | RefCell<Vec<(Ty<'tcx>, Span, traits::ObligationCauseCode<'tcx>)>>, | |
41 | ||
42 | // When we process a call like `c()` where `c` is a closure type, | |
43 | // we may not have decided yet whether `c` is a `Fn`, `FnMut`, or | |
44 | // `FnOnce` closure. In that case, we defer full resolution of the | |
45 | // call until upvar inference can kick in and make the | |
46 | // decision. We keep these deferred resolutions grouped by the | |
47 | // def-id of the closure, so that once we decide, we can easily go | |
48 | // back and process them. | |
49 | pub(super) deferred_call_resolutions: RefCell<DefIdMap<Vec<DeferredCallResolution<'tcx>>>>, | |
50 | ||
51 | pub(super) deferred_cast_checks: RefCell<Vec<super::cast::CastCheck<'tcx>>>, | |
52 | ||
53 | pub(super) deferred_generator_interiors: | |
54 | RefCell<Vec<(hir::BodyId, Ty<'tcx>, hir::GeneratorKind)>>, | |
55 | ||
1b1a35ee | 56 | pub(super) body_id: Option<hir::BodyId>, |
c295e0f8 XL |
57 | |
58 | /// Whenever we introduce an adjustment from `!` into a type variable, | |
59 | /// we record that type variable here. This is later used to inform | |
60 | /// fallback. See the `fallback` module for details. | |
61 | pub(super) diverging_type_vars: RefCell<FxHashSet<Ty<'tcx>>>, | |
1b1a35ee XL |
62 | } |
63 | ||
64 | impl<'a, 'tcx> Deref for Inherited<'a, 'tcx> { | |
65 | type Target = InferCtxt<'a, 'tcx>; | |
66 | fn deref(&self) -> &Self::Target { | |
67 | &self.infcx | |
68 | } | |
69 | } | |
70 | ||
71 | /// Helper type of a temporary returned by `Inherited::build(...)`. | |
72 | /// Necessary because we can't write the following bound: | |
73 | /// `F: for<'b, 'tcx> where 'tcx FnOnce(Inherited<'b, 'tcx>)`. | |
74 | pub struct InheritedBuilder<'tcx> { | |
75 | infcx: infer::InferCtxtBuilder<'tcx>, | |
76 | def_id: LocalDefId, | |
77 | } | |
78 | ||
a2a8927a | 79 | impl<'tcx> Inherited<'_, 'tcx> { |
1b1a35ee XL |
80 | pub fn build(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> InheritedBuilder<'tcx> { |
81 | let hir_owner = tcx.hir().local_def_id_to_hir_id(def_id).owner; | |
82 | ||
83 | InheritedBuilder { | |
84 | infcx: tcx.infer_ctxt().with_fresh_in_progress_typeck_results(hir_owner), | |
85 | def_id, | |
86 | } | |
87 | } | |
88 | } | |
89 | ||
90 | impl<'tcx> InheritedBuilder<'tcx> { | |
91 | pub fn enter<F, R>(&mut self, f: F) -> R | |
92 | where | |
93 | F: for<'a> FnOnce(Inherited<'a, 'tcx>) -> R, | |
94 | { | |
95 | let def_id = self.def_id; | |
96 | self.infcx.enter(|infcx| f(Inherited::new(infcx, def_id))) | |
97 | } | |
98 | } | |
99 | ||
a2a8927a | 100 | impl<'a, 'tcx> Inherited<'a, 'tcx> { |
1b1a35ee XL |
101 | pub(super) fn new(infcx: InferCtxt<'a, 'tcx>, def_id: LocalDefId) -> Self { |
102 | let tcx = infcx.tcx; | |
103 | let item_id = tcx.hir().local_def_id_to_hir_id(def_id); | |
104 | let body_id = tcx.hir().maybe_body_owned_by(item_id); | |
105 | ||
106 | Inherited { | |
107 | typeck_results: MaybeInProgressTables { | |
108 | maybe_typeck_results: infcx.in_progress_typeck_results, | |
109 | }, | |
110 | infcx, | |
6a06907d | 111 | fulfillment_cx: RefCell::new(<dyn TraitEngine<'_>>::new(tcx)), |
1b1a35ee XL |
112 | locals: RefCell::new(Default::default()), |
113 | deferred_sized_obligations: RefCell::new(Vec::new()), | |
114 | deferred_call_resolutions: RefCell::new(Default::default()), | |
115 | deferred_cast_checks: RefCell::new(Vec::new()), | |
116 | deferred_generator_interiors: RefCell::new(Vec::new()), | |
c295e0f8 | 117 | diverging_type_vars: RefCell::new(Default::default()), |
1b1a35ee XL |
118 | body_id, |
119 | } | |
120 | } | |
121 | ||
122 | pub(super) fn register_predicate(&self, obligation: traits::PredicateObligation<'tcx>) { | |
123 | debug!("register_predicate({:?})", obligation); | |
124 | if obligation.has_escaping_bound_vars() { | |
125 | span_bug!(obligation.cause.span, "escaping bound vars in predicate {:?}", obligation); | |
126 | } | |
127 | self.fulfillment_cx.borrow_mut().register_predicate_obligation(self, obligation); | |
128 | } | |
129 | ||
130 | pub(super) fn register_predicates<I>(&self, obligations: I) | |
131 | where | |
132 | I: IntoIterator<Item = traits::PredicateObligation<'tcx>>, | |
133 | { | |
134 | for obligation in obligations { | |
135 | self.register_predicate(obligation); | |
136 | } | |
137 | } | |
138 | ||
139 | pub(super) fn register_infer_ok_obligations<T>(&self, infer_ok: InferOk<'tcx, T>) -> T { | |
140 | self.register_predicates(infer_ok.obligations); | |
141 | infer_ok.value | |
142 | } | |
143 | ||
144 | pub(super) fn normalize_associated_types_in<T>( | |
145 | &self, | |
146 | span: Span, | |
147 | body_id: hir::HirId, | |
148 | param_env: ty::ParamEnv<'tcx>, | |
fc512014 | 149 | value: T, |
1b1a35ee XL |
150 | ) -> T |
151 | where | |
152 | T: TypeFoldable<'tcx>, | |
153 | { | |
136023e0 XL |
154 | self.normalize_associated_types_in_with_cause( |
155 | ObligationCause::misc(span, body_id), | |
156 | param_env, | |
157 | value, | |
158 | ) | |
159 | } | |
160 | ||
161 | pub(super) fn normalize_associated_types_in_with_cause<T>( | |
162 | &self, | |
163 | cause: ObligationCause<'tcx>, | |
164 | param_env: ty::ParamEnv<'tcx>, | |
165 | value: T, | |
166 | ) -> T | |
167 | where | |
168 | T: TypeFoldable<'tcx>, | |
169 | { | |
170 | let ok = self.partially_normalize_associated_types_in(cause, param_env, value); | |
171 | debug!(?ok); | |
1b1a35ee XL |
172 | self.register_infer_ok_obligations(ok) |
173 | } | |
174 | } |