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
use middle::ty;
use syntax::ast::{Item, ItemImpl};
use syntax::ast;
use syntax::ast_util;
use syntax::visit;
use util::ppaux::UserString;
pub fn check(tcx: &ty::ctxt) {
let mut orphan = UnsafetyChecker { tcx: tcx };
visit::walk_crate(&mut orphan, tcx.map.krate());
}
struct UnsafetyChecker<'cx, 'tcx:'cx> {
tcx: &'cx ty::ctxt<'tcx>
}
impl<'cx, 'tcx, 'v> UnsafetyChecker<'cx, 'tcx> {
fn check_unsafety_coherence(&mut self, item: &'v ast::Item,
unsafety: ast::Unsafety,
polarity: ast::ImplPolarity) {
match ty::impl_trait_ref(self.tcx, ast_util::local_def(item.id)) {
None => {
match unsafety {
ast::Unsafety::Normal => { }
ast::Unsafety::Unsafe => {
span_err!(self.tcx.sess, item.span, E0197,
"inherent impls cannot be declared as unsafe");
}
}
}
Some(trait_ref) => {
let trait_def = ty::lookup_trait_def(self.tcx, trait_ref.def_id);
match (trait_def.unsafety, unsafety, polarity) {
(ast::Unsafety::Unsafe,
ast::Unsafety::Unsafe, ast::ImplPolarity::Negative) => {
span_err!(self.tcx.sess, item.span, E0198,
"negative implementations are not unsafe");
}
(ast::Unsafety::Normal, ast::Unsafety::Unsafe, _) => {
span_err!(self.tcx.sess, item.span, E0199,
"implementing the trait `{}` is not unsafe",
trait_ref.user_string(self.tcx));
}
(ast::Unsafety::Unsafe,
ast::Unsafety::Normal, ast::ImplPolarity::Positive) => {
span_err!(self.tcx.sess, item.span, E0200,
"the trait `{}` requires an `unsafe impl` declaration",
trait_ref.user_string(self.tcx));
}
(ast::Unsafety::Unsafe,
ast::Unsafety::Normal, ast::ImplPolarity::Negative) |
(ast::Unsafety::Unsafe,
ast::Unsafety::Unsafe, ast::ImplPolarity::Positive) |
(ast::Unsafety::Normal, ast::Unsafety::Normal, _) => {
}
}
}
}
}
}
impl<'cx, 'tcx,'v> visit::Visitor<'v> for UnsafetyChecker<'cx, 'tcx> {
fn visit_item(&mut self, item: &'v ast::Item) {
match item.node {
ast::ItemDefaultImpl(unsafety, _) => {
self.check_unsafety_coherence(item, unsafety, ast::ImplPolarity::Positive);
}
ast::ItemImpl(unsafety, polarity, _, _, _, _) => {
self.check_unsafety_coherence(item, unsafety, polarity);
}
_ => { }
}
visit::walk_item(self, item);
}
}