move datalog fact generation into a legacy module

1 files changed, 1 insertions, 184 deletions

diff --git a/compiler/rustc_borrowck/src/polonius/mod.rs b/compiler/rustc_borrowck/src/polonius/mod.rs
index 9fccc00bdaf..9c1583f1988 100644
--- a/compiler/rustc_borrowck/src/polonius/mod.rs
+++ b/compiler/rustc_borrowck/src/polonius/mod.rs
@@ -1,184 +1 @@
-//! Functions dedicated to fact generation for the `-Zpolonius=legacy` datalog implementation.
-//!
-//! Will be removed in the future, once the in-tree `-Zpolonius=next` implementation reaches feature
-//! parity.
-
-use rustc_middle::mir::{Body, LocalKind, Location, START_BLOCK};
-use rustc_middle::ty::TyCtxt;
-use rustc_mir_dataflow::move_paths::{InitKind, InitLocation, MoveData};
-use tracing::debug;
-
-use crate::borrow_set::BorrowSet;
-use crate::facts::{AllFacts, PoloniusRegionVid};
-use crate::location::LocationTable;
-use crate::type_check::free_region_relations::UniversalRegionRelations;
-
-mod loan_invalidations;
-mod loan_kills;
-
-/// When requested, emit most of the facts needed by polonius:
-/// - moves and assignments
-/// - universal regions and their relations
-/// - CFG points and edges
-/// - loan kills
-/// - loan invalidations
-///
-/// The rest of the facts are emitted during typeck and liveness.
-pub(crate) fn emit_facts<'tcx>(
-    all_facts: &mut Option<AllFacts>,
-    tcx: TyCtxt<'tcx>,
-    location_table: &LocationTable,
-    body: &Body<'tcx>,
-    borrow_set: &BorrowSet<'tcx>,
-    move_data: &MoveData<'_>,
-    universal_region_relations: &UniversalRegionRelations<'_>,
-) {
-    let Some(all_facts) = all_facts else {
-        // We don't do anything if there are no facts to fill.
-        return;
-    };
-    let _prof_timer = tcx.prof.generic_activity("polonius_fact_generation");
-    emit_move_facts(all_facts, move_data, location_table, body);
-    emit_universal_region_facts(all_facts, borrow_set, universal_region_relations);
-    emit_cfg_and_loan_kills_facts(all_facts, tcx, location_table, body, borrow_set);
-    emit_loan_invalidations_facts(all_facts, tcx, location_table, body, borrow_set);
-}
-
-/// Emit facts needed for move/init analysis: moves and assignments.
-fn emit_move_facts(
-    all_facts: &mut AllFacts,
-    move_data: &MoveData<'_>,
-    location_table: &LocationTable,
-    body: &Body<'_>,
-) {
-    all_facts
-        .path_is_var
-        .extend(move_data.rev_lookup.iter_locals_enumerated().map(|(l, r)| (r, l)));
-
-    for (child, move_path) in move_data.move_paths.iter_enumerated() {
-        if let Some(parent) = move_path.parent {
-            all_facts.child_path.push((child, parent));
-        }
-    }
-
-    let fn_entry_start =
-        location_table.start_index(Location { block: START_BLOCK, statement_index: 0 });
-
-    // initialized_at
-    for init in move_data.inits.iter() {
-        match init.location {
-            InitLocation::Statement(location) => {
-                let block_data = &body[location.block];
-                let is_terminator = location.statement_index == block_data.statements.len();
-
-                if is_terminator && init.kind == InitKind::NonPanicPathOnly {
-                    // We are at the terminator of an init that has a panic path,
-                    // and where the init should not happen on panic
-
-                    for successor in block_data.terminator().successors() {
-                        if body[successor].is_cleanup {
-                            continue;
-                        }
-
-                        // The initialization happened in (or rather, when arriving at)
-                        // the successors, but not in the unwind block.
-                        let first_statement = Location { block: successor, statement_index: 0 };
-                        all_facts
-                            .path_assigned_at_base
-                            .push((init.path, location_table.start_index(first_statement)));
-                    }
-                } else {
-                    // In all other cases, the initialization just happens at the
-                    // midpoint, like any other effect.
-                    all_facts
-                        .path_assigned_at_base
-                        .push((init.path, location_table.mid_index(location)));
-                }
-            }
-            // Arguments are initialized on function entry
-            InitLocation::Argument(local) => {
-                assert!(body.local_kind(local) == LocalKind::Arg);
-                all_facts.path_assigned_at_base.push((init.path, fn_entry_start));
-            }
-        }
-    }
-
-    for (local, path) in move_data.rev_lookup.iter_locals_enumerated() {
-        if body.local_kind(local) != LocalKind::Arg {
-            // Non-arguments start out deinitialised; we simulate this with an
-            // initial move:
-            all_facts.path_moved_at_base.push((path, fn_entry_start));
-        }
-    }
-
-    // moved_out_at
-    // deinitialisation is assumed to always happen!
-    all_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.
-fn emit_universal_region_facts(
-    all_facts: &mut AllFacts,
-    borrow_set: &BorrowSet<'_>,
-    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.
-    //
-    let universal_regions = &universal_region_relations.universal_regions;
-    all_facts
-        .universal_region
-        .extend(universal_regions.universal_regions_iter().map(PoloniusRegionVid::from));
-    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_iter() {
-        let universal_region_idx = universal_region.index();
-        let placeholder_loan_idx = borrow_count + universal_region_idx;
-        all_facts.placeholder.push((universal_region.into(), 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.into(), fr2.into()));
-        }
-    }
-}
-
-/// Emit facts about loan invalidations.
-fn emit_loan_invalidations_facts<'tcx>(
-    all_facts: &mut AllFacts,
-    tcx: TyCtxt<'tcx>,
-    location_table: &LocationTable,
-    body: &Body<'tcx>,
-    borrow_set: &BorrowSet<'tcx>,
-) {
-    loan_invalidations::emit_loan_invalidations(tcx, all_facts, location_table, body, borrow_set);
-}
-
-/// Emit facts about CFG points and edges, as well as locations where loans are killed.
-fn emit_cfg_and_loan_kills_facts<'tcx>(
-    all_facts: &mut AllFacts,
-    tcx: TyCtxt<'tcx>,
-    location_table: &LocationTable,
-    body: &Body<'tcx>,
-    borrow_set: &BorrowSet<'tcx>,
-) {
-    loan_kills::emit_loan_kills(tcx, all_facts, location_table, body, borrow_set);
-}
+pub(crate) mod legacy;