mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

extract polonius universal regions fact generation

Browse Source
This commit is contained in:
Rémy Rakic 2023-11-23 11:28:53 +00:00
parent 3de68e074a
commit 459a616c4f
2 changed files with 50 additions and 35 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
compiler/rustc_borrowck/src/nll.rs
View File

@ -127,42 +127,13 @@ pub(crate) fn compute_regions<'cx, 'tcx>(
if let Some(all_facts) = &mut all_facts {
let _prof_timer = infcx.tcx.prof.generic_activity("polonius_fact_generation");
all_facts.universal_region.extend(universal_regions.universal_regions());
polonius::emit_move_facts(all_facts, move_data, location_table, body);
// Emit universal regions facts, and their relations, for Polonius.
//
// 1: universal regions are modeled in Polonius as a pair:
// - the universal region vid itself.
// - a "placeholder loan" associated to this universal region. Since they don't exist in
// the `borrow_set`, their `BorrowIndex` are synthesized as the universal region index
// added to the existing number of loans, as if they succeeded them in the set.
//
let borrow_count = borrow_set.len();
debug!(
"compute_regions: polonius placeholders, num_universals={}, borrow_count={}",
universal_regions.len(),
borrow_count
polonius::emit_universal_region_facts(
all_facts,
borrow_set,
&universal_regions,
&universal_region_relations,
);
for universal_region in universal_regions.universal_regions() {
let universal_region_idx = universal_region.index();
let placeholder_loan_idx = borrow_count + universal_region_idx;
all_facts.placeholder.push((universal_region, placeholder_loan_idx.into()));
}
// 2: the universal region relations `outlives` constraints are emitted as
// `known_placeholder_subset` facts.
for (fr1, fr2) in universal_region_relations.known_outlives() {
if fr1 != fr2 {
debug!(
"compute_regions: emitting polonius `known_placeholder_subset` \
fr1={:?}, fr2={:?}",
fr1, fr2
);
all_facts.known_placeholder_subset.push((fr1, fr2));
}
}
}
// Create the region inference context, taking ownership of the

46
compiler/rustc_borrowck/src/nll/polonius.rs
View File

@ -6,10 +6,13 @@
use rustc_middle::mir::{Body, LocalKind, Location, START_BLOCK};
use rustc_mir_dataflow::move_paths::{InitKind, InitLocation, MoveData};
use crate::borrow_set::BorrowSet;
use crate::facts::AllFacts;
use crate::location::LocationTable;
use crate::type_check::free_region_relations::UniversalRegionRelations;
use crate::universal_regions::UniversalRegions;
/// Emit polonius facts needed for move/init analysis: moves and assignments.
/// Emit facts needed for move/init analysis: moves and assignments.
pub(crate) fn emit_move_facts(
all_facts: &mut AllFacts,
move_data: &MoveData<'_>,
@ -82,3 +85,44 @@ pub(crate) fn emit_move_facts(
.path_moved_at_base
.extend(move_data.moves.iter().map(|mo| (mo.path, location_table.mid_index(mo.source))));
}
/// Emit universal regions facts, and their relations.
pub(crate) fn emit_universal_region_facts(
all_facts: &mut AllFacts,
borrow_set: &BorrowSet<'_>,
universal_regions: &UniversalRegions<'_>,
universal_region_relations: &UniversalRegionRelations<'_>,
) {
// 1: universal regions are modeled in Polonius as a pair:
// - the universal region vid itself.
// - a "placeholder loan" associated to this universal region. Since they don't exist in
// the `borrow_set`, their `BorrowIndex` are synthesized as the universal region index
// added to the existing number of loans, as if they succeeded them in the set.
//
all_facts.universal_region.extend(universal_regions.universal_regions());
let borrow_count = borrow_set.len();
debug!(
"emit_universal_region_facts: polonius placeholders, num_universals={}, borrow_count={}",
universal_regions.len(),
borrow_count
);
for universal_region in universal_regions.universal_regions() {
let universal_region_idx = universal_region.index();
let placeholder_loan_idx = borrow_count + universal_region_idx;
all_facts.placeholder.push((universal_region, placeholder_loan_idx.into()));
}
// 2: the universal region relations `outlives` constraints are emitted as
// `known_placeholder_subset` facts.
for (fr1, fr2) in universal_region_relations.known_outlives() {
if fr1 != fr2 {
debug!(
"emit_universal_region_facts: emitting polonius `known_placeholder_subset` \
fr1={:?}, fr2={:?}",
fr1, fr2
);
all_facts.known_placeholder_subset.push((fr1, fr2));
}
}
}