1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
|
use rustc_data_structures::fx::FxHashMap;
use rustc_hir as hir;
use rustc_hir::def::DefKind;
use rustc_hir::def_id::{DefId, LocalDefId};
use rustc_hir::definitions::DefPathData;
use rustc_hir::intravisit::{self, Visitor};
use rustc_middle::ty::{self, DefIdTree, TyCtxt};
pub fn provide(providers: &mut ty::query::Providers) {
*providers = ty::query::Providers {
associated_item,
associated_item_def_ids,
associated_items,
associated_items_for_impl_trait_in_trait,
associated_item_for_impl_trait_in_trait,
impl_item_implementor_ids,
..*providers
};
}
fn associated_item_def_ids(tcx: TyCtxt<'_>, def_id: DefId) -> &[DefId] {
let item = tcx.hir().expect_item(def_id.expect_local());
match item.kind {
hir::ItemKind::Trait(.., ref trait_item_refs) => tcx.arena.alloc_from_iter(
trait_item_refs.iter().map(|trait_item_ref| trait_item_ref.id.owner_id.to_def_id()),
),
hir::ItemKind::Impl(ref impl_) => tcx.arena.alloc_from_iter(
impl_.items.iter().map(|impl_item_ref| impl_item_ref.id.owner_id.to_def_id()),
),
_ => span_bug!(item.span, "associated_item_def_ids: not impl or trait"),
}
}
fn associated_items(tcx: TyCtxt<'_>, def_id: DefId) -> ty::AssocItems {
if tcx.is_trait_alias(def_id) {
ty::AssocItems::new(Vec::new())
} else {
let items = tcx.associated_item_def_ids(def_id).iter().map(|did| tcx.associated_item(*did));
ty::AssocItems::new(items)
}
}
fn impl_item_implementor_ids(tcx: TyCtxt<'_>, impl_id: DefId) -> FxHashMap<DefId, DefId> {
tcx.associated_items(impl_id)
.in_definition_order()
.filter_map(|item| item.trait_item_def_id.map(|trait_item| (trait_item, item.def_id)))
.collect()
}
fn associated_item(tcx: TyCtxt<'_>, def_id: DefId) -> ty::AssocItem {
let id = tcx.hir().local_def_id_to_hir_id(def_id.expect_local());
let parent_def_id = tcx.hir().get_parent_item(id);
let parent_item = tcx.hir().expect_item(parent_def_id.def_id);
match parent_item.kind {
hir::ItemKind::Impl(ref impl_) => {
if let Some(impl_item_ref) =
impl_.items.iter().find(|i| i.id.owner_id.to_def_id() == def_id)
{
let assoc_item = associated_item_from_impl_item_ref(impl_item_ref);
debug_assert_eq!(assoc_item.def_id, def_id);
return assoc_item;
}
}
hir::ItemKind::Trait(.., ref trait_item_refs) => {
if let Some(trait_item_ref) =
trait_item_refs.iter().find(|i| i.id.owner_id.to_def_id() == def_id)
{
let assoc_item = associated_item_from_trait_item_ref(trait_item_ref);
debug_assert_eq!(assoc_item.def_id, def_id);
return assoc_item;
}
}
_ => {}
}
span_bug!(
parent_item.span,
"unexpected parent of trait or impl item or item not found: {:?}",
parent_item.kind
)
}
fn associated_item_from_trait_item_ref(trait_item_ref: &hir::TraitItemRef) -> ty::AssocItem {
let owner_id = trait_item_ref.id.owner_id;
let (kind, has_self) = match trait_item_ref.kind {
hir::AssocItemKind::Const => (ty::AssocKind::Const, false),
hir::AssocItemKind::Fn { has_self } => (ty::AssocKind::Fn, has_self),
hir::AssocItemKind::Type => (ty::AssocKind::Type, false),
};
ty::AssocItem {
name: trait_item_ref.ident.name,
kind,
def_id: owner_id.to_def_id(),
trait_item_def_id: Some(owner_id.to_def_id()),
container: ty::TraitContainer,
fn_has_self_parameter: has_self,
}
}
fn associated_item_from_impl_item_ref(impl_item_ref: &hir::ImplItemRef) -> ty::AssocItem {
let def_id = impl_item_ref.id.owner_id;
let (kind, has_self) = match impl_item_ref.kind {
hir::AssocItemKind::Const => (ty::AssocKind::Const, false),
hir::AssocItemKind::Fn { has_self } => (ty::AssocKind::Fn, has_self),
hir::AssocItemKind::Type => (ty::AssocKind::Type, false),
};
ty::AssocItem {
name: impl_item_ref.ident.name,
kind,
def_id: def_id.to_def_id(),
trait_item_def_id: impl_item_ref.trait_item_def_id,
container: ty::ImplContainer,
fn_has_self_parameter: has_self,
}
}
/// Given an `fn_def_id` of a trait or of an impl that implements a given trait:
/// if `fn_def_id` is the def id of a function defined inside a trait, then it creates and returns
/// the associated items that correspond to each impl trait in return position for that trait.
/// if `fn_def_id` is the def id of a function defined inside an impl that implements a trait, then it
/// creates and returns the associated items that correspond to each impl trait in return position
/// of the implemented trait.
fn associated_items_for_impl_trait_in_trait(tcx: TyCtxt<'_>, fn_def_id: DefId) -> &'_ [DefId] {
let parent_def_id = tcx.parent(fn_def_id);
match tcx.def_kind(parent_def_id) {
DefKind::Trait => {
struct RPITVisitor {
rpits: Vec<LocalDefId>,
}
impl<'v> Visitor<'v> for RPITVisitor {
fn visit_ty(&mut self, ty: &'v hir::Ty<'v>) {
if let hir::TyKind::OpaqueDef(item_id, _, _) = ty.kind {
self.rpits.push(item_id.owner_id.def_id)
}
intravisit::walk_ty(self, ty)
}
}
let mut visitor = RPITVisitor { rpits: Vec::new() };
if let Some(output) = tcx.hir().get_fn_output(fn_def_id.expect_local()) {
visitor.visit_fn_ret_ty(output);
tcx.arena.alloc_from_iter(visitor.rpits.iter().map(|opaque_ty_def_id| {
tcx.associated_item_for_impl_trait_in_trait(opaque_ty_def_id).to_def_id()
}))
} else {
&[]
}
}
DefKind::Impl { .. } => {
let Some(trait_fn_def_id) = tcx.associated_item(fn_def_id).trait_item_def_id else { return &[] };
tcx.arena.alloc_from_iter(
tcx.associated_items_for_impl_trait_in_trait(trait_fn_def_id).iter().map(
move |trait_assoc_def_id| {
impl_associated_item_for_impl_trait_in_trait(
tcx,
trait_assoc_def_id.expect_local(),
fn_def_id.expect_local(),
)
.to_def_id()
},
),
)
}
def_kind => bug!(
"associated_items_for_impl_trait_in_trait: {:?} should be Trait or Impl but is {:?}",
parent_def_id,
def_kind
),
}
}
/// Given an `opaque_ty_def_id` corresponding to an impl trait in trait, create and return the
/// corresponding associated item.
fn associated_item_for_impl_trait_in_trait(
tcx: TyCtxt<'_>,
opaque_ty_def_id: LocalDefId,
) -> LocalDefId {
let fn_def_id = tcx.impl_trait_in_trait_parent(opaque_ty_def_id.to_def_id());
let trait_def_id = tcx.parent(fn_def_id);
assert_eq!(tcx.def_kind(trait_def_id), DefKind::Trait);
let span = tcx.def_span(opaque_ty_def_id);
let trait_assoc_ty =
tcx.at(span).create_def(trait_def_id.expect_local(), DefPathData::ImplTraitAssocTy);
trait_assoc_ty.def_id()
}
/// Given an `trait_assoc_def_id` that corresponds to a previously synthethized impl trait in trait
/// into an associated type and an `impl_def_id` corresponding to an impl block, create and return
/// the corresponding associated item inside the impl block.
fn impl_associated_item_for_impl_trait_in_trait(
tcx: TyCtxt<'_>,
trait_assoc_def_id: LocalDefId,
impl_fn_def_id: LocalDefId,
) -> LocalDefId {
let impl_def_id = tcx.local_parent(impl_fn_def_id);
let span = tcx.def_span(trait_assoc_def_id);
let impl_assoc_ty = tcx.at(span).create_def(impl_def_id, DefPathData::ImplTraitAssocTy);
impl_assoc_ty.def_id()
}
|
