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
|
//! This file provides API for compiler consumers.
use rustc_data_structures::fx::FxHashMap;
use rustc_hir::def_id::LocalDefId;
use rustc_index::IndexVec;
use rustc_middle::bug;
use rustc_middle::mir::{Body, Promoted};
use rustc_middle::ty::TyCtxt;
pub use super::borrow_set::{BorrowData, BorrowSet, TwoPhaseActivation};
pub use super::constraints::OutlivesConstraint;
pub use super::dataflow::{BorrowIndex, Borrows, calculate_borrows_out_of_scope_at_location};
pub use super::place_ext::PlaceExt;
pub use super::places_conflict::{PlaceConflictBias, places_conflict};
pub use super::polonius::legacy::{
PoloniusFacts as PoloniusInput, PoloniusLocationTable, PoloniusOutput, PoloniusRegionVid,
RichLocation, RustcFacts,
};
pub use super::region_infer::RegionInferenceContext;
use crate::BorrowCheckRootCtxt;
/// Struct used during mir borrowck to collect bodies with facts for a typeck root and all
/// its nested bodies.
pub(crate) struct BorrowckConsumer<'tcx> {
options: ConsumerOptions,
bodies: FxHashMap<LocalDefId, BodyWithBorrowckFacts<'tcx>>,
}
impl<'tcx> BorrowckConsumer<'tcx> {
pub(crate) fn new(options: ConsumerOptions) -> Self {
Self { options, bodies: Default::default() }
}
pub(crate) fn insert_body(&mut self, def_id: LocalDefId, body: BodyWithBorrowckFacts<'tcx>) {
if self.bodies.insert(def_id, body).is_some() {
bug!("unexpected previous body for {def_id:?}");
}
}
/// Should the Polonius input facts be computed?
pub(crate) fn polonius_input(&self) -> bool {
matches!(
self.options,
ConsumerOptions::PoloniusInputFacts | ConsumerOptions::PoloniusOutputFacts
)
}
/// Should we run Polonius and collect the output facts?
pub(crate) fn polonius_output(&self) -> bool {
matches!(self.options, ConsumerOptions::PoloniusOutputFacts)
}
}
/// Options determining the output behavior of [`get_bodies_with_borrowck_facts`].
///
/// If executing under `-Z polonius` the choice here has no effect, and everything as if
/// [`PoloniusOutputFacts`](ConsumerOptions::PoloniusOutputFacts) had been selected
/// will be retrieved.
#[derive(Debug, Copy, Clone)]
pub enum ConsumerOptions {
/// Retrieve the [`Body`] along with the [`BorrowSet`]
/// and [`RegionInferenceContext`]. If you would like the body only, use
/// [`TyCtxt::mir_promoted`].
///
/// These can be used in conjunction with [`calculate_borrows_out_of_scope_at_location`].
RegionInferenceContext,
/// The recommended option. Retrieves the maximal amount of information
/// without significant slowdowns.
///
/// Implies [`RegionInferenceContext`](ConsumerOptions::RegionInferenceContext),
/// and additionally retrieve the [`PoloniusLocationTable`] and [`PoloniusInput`] that
/// would be given to Polonius. Critically, this does not run Polonius, which
/// one may want to avoid due to performance issues on large bodies.
PoloniusInputFacts,
/// Implies [`PoloniusInputFacts`](ConsumerOptions::PoloniusInputFacts),
/// and additionally runs Polonius to calculate the [`PoloniusOutput`].
PoloniusOutputFacts,
}
/// A `Body` with information computed by the borrow checker. This struct is
/// intended to be consumed by compiler consumers.
///
/// We need to include the MIR body here because the region identifiers must
/// match the ones in the Polonius facts.
pub struct BodyWithBorrowckFacts<'tcx> {
/// A mir body that contains region identifiers.
pub body: Body<'tcx>,
/// The mir bodies of promoteds.
pub promoted: IndexVec<Promoted, Body<'tcx>>,
/// The set of borrows occurring in `body` with data about them.
pub borrow_set: BorrowSet<'tcx>,
/// Context generated during borrowck, intended to be passed to
/// [`calculate_borrows_out_of_scope_at_location`].
pub region_inference_context: RegionInferenceContext<'tcx>,
/// The table that maps Polonius points to locations in the table.
/// Populated when using [`ConsumerOptions::PoloniusInputFacts`]
/// or [`ConsumerOptions::PoloniusOutputFacts`].
pub location_table: Option<PoloniusLocationTable>,
/// Polonius input facts.
/// Populated when using [`ConsumerOptions::PoloniusInputFacts`]
/// or [`ConsumerOptions::PoloniusOutputFacts`].
pub input_facts: Option<Box<PoloniusInput>>,
/// Polonius output facts. Populated when using
/// [`ConsumerOptions::PoloniusOutputFacts`].
pub output_facts: Option<Box<PoloniusOutput>>,
}
/// This function computes borrowck facts for the given def id and all its nested bodies.
/// It must be called with a typeck root which will then borrowck all nested bodies as well.
/// The [`ConsumerOptions`] determine which facts are returned. This function makes a copy
/// of the bodies because it needs to regenerate the region identifiers. It should never be
/// invoked during a typical compilation session due to the unnecessary overhead of
/// returning [`BodyWithBorrowckFacts`].
///
/// Note:
/// * This function will panic if the required bodies were already stolen. This
/// can, for example, happen when requesting a body of a `const` function
/// because they are evaluated during typechecking. The panic can be avoided
/// by overriding the `mir_borrowck` query. You can find a complete example
/// that shows how to do this at `tests/ui-fulldeps/obtain-borrowck.rs`.
///
/// * Polonius is highly unstable, so expect regular changes in its signature or other details.
pub fn get_bodies_with_borrowck_facts(
tcx: TyCtxt<'_>,
root_def_id: LocalDefId,
options: ConsumerOptions,
) -> FxHashMap<LocalDefId, BodyWithBorrowckFacts<'_>> {
let mut root_cx =
BorrowCheckRootCtxt::new(tcx, root_def_id, Some(BorrowckConsumer::new(options)));
root_cx.do_mir_borrowck();
root_cx.consumer.unwrap().bodies
}
|
