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Commit | Line | Data |
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1b1a35ee | 1 | use super::callee::DeferredCallResolution; |
1b1a35ee | 2 | |
c295e0f8 | 3 | use rustc_data_structures::fx::FxHashSet; |
1b1a35ee | 4 | use rustc_hir as hir; |
064997fb | 5 | use rustc_hir::def_id::LocalDefId; |
1b1a35ee XL |
6 | use rustc_hir::HirIdMap; |
7 | use rustc_infer::infer; | |
8 | use rustc_infer::infer::{InferCtxt, InferOk, TyCtxtInferExt}; | |
9 | use rustc_middle::ty::fold::TypeFoldable; | |
064997fb | 10 | use rustc_middle::ty::visit::TypeVisitable; |
94222f64 | 11 | use rustc_middle::ty::{self, Ty, TyCtxt}; |
064997fb | 12 | use rustc_span::def_id::LocalDefIdMap; |
1b1a35ee XL |
13 | use rustc_span::{self, Span}; |
14 | use rustc_trait_selection::infer::InferCtxtExt as _; | |
136023e0 | 15 | use rustc_trait_selection::traits::{self, ObligationCause, TraitEngine, TraitEngineExt}; |
1b1a35ee XL |
16 | |
17 | use std::cell::RefCell; | |
18 | use std::ops::Deref; | |
19 | ||
20 | /// Closures defined within the function. For example: | |
04454e1e FG |
21 | /// ```ignore (illustrative) |
22 | /// fn foo() { | |
23 | /// bar(move|| { ... }) | |
24 | /// } | |
25 | /// ``` | |
1b1a35ee XL |
26 | /// Here, the function `foo()` and the closure passed to |
27 | /// `bar()` will each have their own `FnCtxt`, but they will | |
28 | /// share the inherited fields. | |
29 | pub struct Inherited<'a, 'tcx> { | |
30 | pub(super) infcx: InferCtxt<'a, 'tcx>, | |
31 | ||
064997fb | 32 | pub(super) typeck_results: &'a RefCell<ty::TypeckResults<'tcx>>, |
1b1a35ee XL |
33 | |
34 | pub(super) locals: RefCell<HirIdMap<super::LocalTy<'tcx>>>, | |
35 | ||
36 | pub(super) fulfillment_cx: RefCell<Box<dyn TraitEngine<'tcx>>>, | |
37 | ||
38 | // Some additional `Sized` obligations badly affect type inference. | |
39 | // These obligations are added in a later stage of typeck. | |
40 | pub(super) deferred_sized_obligations: | |
41 | RefCell<Vec<(Ty<'tcx>, Span, traits::ObligationCauseCode<'tcx>)>>, | |
42 | ||
43 | // When we process a call like `c()` where `c` is a closure type, | |
44 | // we may not have decided yet whether `c` is a `Fn`, `FnMut`, or | |
45 | // `FnOnce` closure. In that case, we defer full resolution of the | |
46 | // call until upvar inference can kick in and make the | |
47 | // decision. We keep these deferred resolutions grouped by the | |
48 | // def-id of the closure, so that once we decide, we can easily go | |
49 | // back and process them. | |
064997fb | 50 | pub(super) deferred_call_resolutions: RefCell<LocalDefIdMap<Vec<DeferredCallResolution<'tcx>>>>, |
1b1a35ee XL |
51 | |
52 | pub(super) deferred_cast_checks: RefCell<Vec<super::cast::CastCheck<'tcx>>>, | |
53 | ||
923072b8 FG |
54 | pub(super) deferred_transmute_checks: RefCell<Vec<(Ty<'tcx>, Ty<'tcx>, Span)>>, |
55 | ||
56 | pub(super) deferred_asm_checks: RefCell<Vec<(&'tcx hir::InlineAsm<'tcx>, hir::HirId)>>, | |
57 | ||
1b1a35ee XL |
58 | pub(super) deferred_generator_interiors: |
59 | RefCell<Vec<(hir::BodyId, Ty<'tcx>, hir::GeneratorKind)>>, | |
60 | ||
1b1a35ee | 61 | pub(super) body_id: Option<hir::BodyId>, |
c295e0f8 XL |
62 | |
63 | /// Whenever we introduce an adjustment from `!` into a type variable, | |
64 | /// we record that type variable here. This is later used to inform | |
65 | /// fallback. See the `fallback` module for details. | |
66 | pub(super) diverging_type_vars: RefCell<FxHashSet<Ty<'tcx>>>, | |
1b1a35ee XL |
67 | } |
68 | ||
69 | impl<'a, 'tcx> Deref for Inherited<'a, 'tcx> { | |
70 | type Target = InferCtxt<'a, 'tcx>; | |
71 | fn deref(&self) -> &Self::Target { | |
72 | &self.infcx | |
73 | } | |
74 | } | |
75 | ||
5e7ed085 FG |
76 | /// A temporary returned by `Inherited::build(...)`. This is necessary |
77 | /// for multiple `InferCtxt` to share the same `in_progress_typeck_results` | |
78 | /// without using `Rc` or something similar. | |
1b1a35ee XL |
79 | pub struct InheritedBuilder<'tcx> { |
80 | infcx: infer::InferCtxtBuilder<'tcx>, | |
81 | def_id: LocalDefId, | |
82 | } | |
83 | ||
a2a8927a | 84 | impl<'tcx> Inherited<'_, 'tcx> { |
1b1a35ee XL |
85 | pub fn build(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> InheritedBuilder<'tcx> { |
86 | let hir_owner = tcx.hir().local_def_id_to_hir_id(def_id).owner; | |
87 | ||
88 | InheritedBuilder { | |
064997fb FG |
89 | infcx: tcx |
90 | .infer_ctxt() | |
91 | .ignoring_regions() | |
92 | .with_fresh_in_progress_typeck_results(hir_owner), | |
1b1a35ee XL |
93 | def_id, |
94 | } | |
95 | } | |
96 | } | |
97 | ||
98 | impl<'tcx> InheritedBuilder<'tcx> { | |
99 | pub fn enter<F, R>(&mut self, f: F) -> R | |
100 | where | |
101 | F: for<'a> FnOnce(Inherited<'a, 'tcx>) -> R, | |
102 | { | |
103 | let def_id = self.def_id; | |
104 | self.infcx.enter(|infcx| f(Inherited::new(infcx, def_id))) | |
105 | } | |
106 | } | |
107 | ||
a2a8927a | 108 | impl<'a, 'tcx> Inherited<'a, 'tcx> { |
064997fb | 109 | fn new(infcx: InferCtxt<'a, 'tcx>, def_id: LocalDefId) -> Self { |
1b1a35ee | 110 | let tcx = infcx.tcx; |
064997fb FG |
111 | let body_id = tcx.hir().maybe_body_owned_by(def_id); |
112 | let typeck_results = | |
113 | infcx.in_progress_typeck_results.expect("building `FnCtxt` without typeck results"); | |
1b1a35ee XL |
114 | |
115 | Inherited { | |
064997fb | 116 | typeck_results, |
1b1a35ee | 117 | infcx, |
6a06907d | 118 | fulfillment_cx: RefCell::new(<dyn TraitEngine<'_>>::new(tcx)), |
1b1a35ee XL |
119 | locals: RefCell::new(Default::default()), |
120 | deferred_sized_obligations: RefCell::new(Vec::new()), | |
121 | deferred_call_resolutions: RefCell::new(Default::default()), | |
122 | deferred_cast_checks: RefCell::new(Vec::new()), | |
923072b8 FG |
123 | deferred_transmute_checks: RefCell::new(Vec::new()), |
124 | deferred_asm_checks: RefCell::new(Vec::new()), | |
1b1a35ee | 125 | deferred_generator_interiors: RefCell::new(Vec::new()), |
c295e0f8 | 126 | diverging_type_vars: RefCell::new(Default::default()), |
1b1a35ee XL |
127 | body_id, |
128 | } | |
129 | } | |
130 | ||
5e7ed085 | 131 | #[instrument(level = "debug", skip(self))] |
1b1a35ee | 132 | pub(super) fn register_predicate(&self, obligation: traits::PredicateObligation<'tcx>) { |
1b1a35ee XL |
133 | if obligation.has_escaping_bound_vars() { |
134 | span_bug!(obligation.cause.span, "escaping bound vars in predicate {:?}", obligation); | |
135 | } | |
136 | self.fulfillment_cx.borrow_mut().register_predicate_obligation(self, obligation); | |
137 | } | |
138 | ||
139 | pub(super) fn register_predicates<I>(&self, obligations: I) | |
140 | where | |
141 | I: IntoIterator<Item = traits::PredicateObligation<'tcx>>, | |
142 | { | |
143 | for obligation in obligations { | |
144 | self.register_predicate(obligation); | |
145 | } | |
146 | } | |
147 | ||
148 | pub(super) fn register_infer_ok_obligations<T>(&self, infer_ok: InferOk<'tcx, T>) -> T { | |
149 | self.register_predicates(infer_ok.obligations); | |
150 | infer_ok.value | |
151 | } | |
152 | ||
153 | pub(super) fn normalize_associated_types_in<T>( | |
154 | &self, | |
155 | span: Span, | |
156 | body_id: hir::HirId, | |
157 | param_env: ty::ParamEnv<'tcx>, | |
fc512014 | 158 | value: T, |
1b1a35ee XL |
159 | ) -> T |
160 | where | |
161 | T: TypeFoldable<'tcx>, | |
162 | { | |
136023e0 XL |
163 | self.normalize_associated_types_in_with_cause( |
164 | ObligationCause::misc(span, body_id), | |
165 | param_env, | |
166 | value, | |
167 | ) | |
168 | } | |
169 | ||
170 | pub(super) fn normalize_associated_types_in_with_cause<T>( | |
171 | &self, | |
172 | cause: ObligationCause<'tcx>, | |
173 | param_env: ty::ParamEnv<'tcx>, | |
174 | value: T, | |
175 | ) -> T | |
176 | where | |
177 | T: TypeFoldable<'tcx>, | |
178 | { | |
179 | let ok = self.partially_normalize_associated_types_in(cause, param_env, value); | |
180 | debug!(?ok); | |
1b1a35ee XL |
181 | self.register_infer_ok_obligations(ok) |
182 | } | |
183 | } |