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
use hir::def_id::{DefId, LOCAL_CRATE};
use rustc::traits;
use rustc::ty::{self, TyCtxt, TypeFoldable};
use rustc::ty::query::Providers;
use syntax::ast;
mod builtin;
mod inherent_impls;
mod inherent_impls_overlap;
mod orphan;
mod unsafety;
fn check_impl<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, node_id: ast::NodeId) {
let impl_def_id = tcx.hir.local_def_id(node_id);
if let Some(trait_ref) = tcx.impl_trait_ref(impl_def_id) {
debug!("(checking implementation) adding impl for trait '{:?}', item '{}'",
trait_ref,
tcx.item_path_str(impl_def_id));
if trait_ref.references_error() {
return;
}
enforce_trait_manually_implementable(tcx, impl_def_id, trait_ref.def_id);
}
}
fn enforce_trait_manually_implementable(tcx: TyCtxt, impl_def_id: DefId, trait_def_id: DefId) {
let did = Some(trait_def_id);
let li = tcx.lang_items();
let span = tcx.sess.source_map().def_span(tcx.span_of_impl(impl_def_id).unwrap());
if did == li.sized_trait() {
struct_span_err!(tcx.sess,
span,
E0322,
"explicit impls for the `Sized` trait are not permitted")
.span_label(span, "impl of 'Sized' not allowed")
.emit();
return;
}
if did == li.unsize_trait() {
struct_span_err!(tcx.sess,
span,
E0328,
"explicit impls for the `Unsize` trait are not permitted")
.span_label(span, "impl of `Unsize` not allowed")
.emit();
return;
}
if tcx.features().unboxed_closures {
return;
}
let trait_name = if did == li.fn_trait() {
"Fn"
} else if did == li.fn_mut_trait() {
"FnMut"
} else if did == li.fn_once_trait() {
"FnOnce"
} else {
return;
};
struct_span_err!(tcx.sess,
span,
E0183,
"manual implementations of `{}` are experimental",
trait_name)
.span_label(span, format!("manual implementations of `{}` are experimental", trait_name))
.help("add `#![feature(unboxed_closures)]` to the crate attributes to enable")
.emit();
}
pub fn provide(providers: &mut Providers) {
use self::builtin::coerce_unsized_info;
use self::inherent_impls::{crate_inherent_impls, inherent_impls};
use self::inherent_impls_overlap::crate_inherent_impls_overlap_check;
*providers = Providers {
coherent_trait,
crate_inherent_impls,
inherent_impls,
crate_inherent_impls_overlap_check,
coerce_unsized_info,
..*providers
};
}
fn coherent_trait<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) {
let impls = tcx.hir.trait_impls(def_id);
for &impl_id in impls {
check_impl(tcx, impl_id);
}
for &impl_id in impls {
check_impl_overlap(tcx, impl_id);
}
builtin::check_trait(tcx, def_id);
}
pub fn check_coherence<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
for &trait_def_id in tcx.hir.krate().trait_impls.keys() {
ty::query::queries::coherent_trait::ensure(tcx, trait_def_id);
}
unsafety::check(tcx);
orphan::check(tcx);
ty::query::queries::crate_inherent_impls::ensure(tcx, LOCAL_CRATE);
ty::query::queries::crate_inherent_impls_overlap_check::ensure(tcx, LOCAL_CRATE);
}
fn check_impl_overlap<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, node_id: ast::NodeId) {
let impl_def_id = tcx.hir.local_def_id(node_id);
let trait_ref = tcx.impl_trait_ref(impl_def_id).unwrap();
let trait_def_id = trait_ref.def_id;
if trait_ref.references_error() {
debug!("coherence: skipping impl {:?} with error {:?}",
impl_def_id, trait_ref);
return
}
tcx.specialization_graph_of(trait_def_id);
if let ty::Dynamic(ref data, ..) = trait_ref.self_ty().sty {
if data.principal().map_or(true, |p| !tcx.is_object_safe(p.def_id())) {
} else {
let mut supertrait_def_ids =
traits::supertrait_def_ids(tcx,
data.principal().unwrap().def_id());
if supertrait_def_ids.any(|d| d == trait_def_id) {
let sp = tcx.sess.source_map().def_span(tcx.span_of_impl(impl_def_id).unwrap());
struct_span_err!(tcx.sess,
sp,
E0371,
"the object type `{}` automatically implements the trait `{}`",
trait_ref.self_ty(),
tcx.item_path_str(trait_def_id))
.span_label(sp, format!("`{}` automatically implements trait `{}`",
trait_ref.self_ty(),
tcx.item_path_str(trait_def_id)))
.emit();
}
}
}
}