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
#![deny(rustc::untranslatable_diagnostic)]
#![deny(rustc::diagnostic_outside_of_impl)]
use crate::BorrowckInferCtxt;
use rustc_index::vec::IndexVec;
use rustc_infer::infer::NllRegionVariableOrigin;
use rustc_middle::mir::visit::{MutVisitor, TyContext};
use rustc_middle::mir::Constant;
use rustc_middle::mir::{Body, Location, Promoted};
use rustc_middle::ty::subst::SubstsRef;
use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable};
use rustc_span::{Span, Symbol};
#[instrument(skip(infcx, body, promoted), level = "debug")]
pub fn renumber_mir<'tcx>(
infcx: &BorrowckInferCtxt<'_, 'tcx>,
body: &mut Body<'tcx>,
promoted: &mut IndexVec<Promoted, Body<'tcx>>,
) {
debug!(?body.arg_count);
let mut visitor = NllVisitor { infcx };
for body in promoted.iter_mut() {
visitor.visit_body(body);
}
visitor.visit_body(body);
}
#[instrument(skip(infcx, get_ctxt_fn), level = "debug")]
pub(crate) fn renumber_regions<'tcx, T, F>(
infcx: &BorrowckInferCtxt<'_, 'tcx>,
value: T,
get_ctxt_fn: F,
) -> T
where
T: TypeFoldable<TyCtxt<'tcx>>,
F: Fn() -> RegionCtxt,
{
infcx.tcx.fold_regions(value, |_region, _depth| {
let origin = NllRegionVariableOrigin::Existential { from_forall: false };
infcx.next_nll_region_var(origin, || get_ctxt_fn())
})
}
#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
pub(crate) enum BoundRegionInfo {
Name(Symbol),
Span(Span),
}
#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
pub(crate) enum RegionCtxt {
Location(Location),
TyContext(TyContext),
Free(Symbol),
Bound(BoundRegionInfo),
LateBound(BoundRegionInfo),
Existential(Option<Symbol>),
Placeholder(BoundRegionInfo),
Unknown,
}
impl RegionCtxt {
pub(crate) fn preference_value(self) -> usize {
let _anon = Symbol::intern("anon");
match self {
RegionCtxt::Unknown => 1,
RegionCtxt::Existential(None) => 2,
RegionCtxt::Existential(Some(_anon)) | RegionCtxt::Free(_anon) => 2,
RegionCtxt::Location(_) => 3,
RegionCtxt::TyContext(_) => 4,
_ => 5,
}
}
}
struct NllVisitor<'a, 'tcx> {
infcx: &'a BorrowckInferCtxt<'a, 'tcx>,
}
impl<'a, 'tcx> NllVisitor<'a, 'tcx> {
fn renumber_regions<T, F>(&mut self, value: T, region_ctxt_fn: F) -> T
where
T: TypeFoldable<TyCtxt<'tcx>>,
F: Fn() -> RegionCtxt,
{
renumber_regions(self.infcx, value, region_ctxt_fn)
}
}
impl<'a, 'tcx> MutVisitor<'tcx> for NllVisitor<'a, 'tcx> {
fn tcx(&self) -> TyCtxt<'tcx> {
self.infcx.tcx
}
#[instrument(skip(self), level = "debug")]
fn visit_ty(&mut self, ty: &mut Ty<'tcx>, ty_context: TyContext) {
*ty = self.renumber_regions(*ty, || RegionCtxt::TyContext(ty_context));
debug!(?ty);
}
#[instrument(skip(self), level = "debug")]
fn visit_substs(&mut self, substs: &mut SubstsRef<'tcx>, location: Location) {
*substs = self.renumber_regions(*substs, || RegionCtxt::Location(location));
debug!(?substs);
}
#[instrument(skip(self), level = "debug")]
fn visit_region(&mut self, region: &mut ty::Region<'tcx>, location: Location) {
let old_region = *region;
*region = self.renumber_regions(old_region, || RegionCtxt::Location(location));
debug!(?region);
}
#[instrument(skip(self), level = "debug")]
fn visit_constant(&mut self, constant: &mut Constant<'tcx>, _location: Location) {
let literal = constant.literal;
constant.literal = self.renumber_regions(literal, || RegionCtxt::Location(_location));
debug!("constant: {:#?}", constant);
}
}