rustc_mir_dataflow/
points.rsuse rustc_index::bit_set::BitSet;
use rustc_index::interval::SparseIntervalMatrix;
use rustc_index::{Idx, IndexVec};
use rustc_middle::mir::{self, BasicBlock, Body, Location};
use crate::framework::{ResultsVisitable, ResultsVisitor, visit_results};
pub struct DenseLocationMap {
statements_before_block: IndexVec<BasicBlock, usize>,
basic_blocks: IndexVec<PointIndex, BasicBlock>,
num_points: usize,
}
impl DenseLocationMap {
#[inline]
pub fn new(body: &Body<'_>) -> Self {
let mut num_points = 0;
let statements_before_block: IndexVec<BasicBlock, usize> = body
.basic_blocks
.iter()
.map(|block_data| {
let v = num_points;
num_points += block_data.statements.len() + 1;
v
})
.collect();
let mut basic_blocks = IndexVec::with_capacity(num_points);
for (bb, bb_data) in body.basic_blocks.iter_enumerated() {
basic_blocks.extend((0..=bb_data.statements.len()).map(|_| bb));
}
Self { statements_before_block, basic_blocks, num_points }
}
#[inline]
pub fn num_points(&self) -> usize {
self.num_points
}
#[inline]
pub fn point_from_location(&self, location: Location) -> PointIndex {
let Location { block, statement_index } = location;
let start_index = self.statements_before_block[block];
PointIndex::new(start_index + statement_index)
}
#[inline]
pub fn entry_point(&self, block: BasicBlock) -> PointIndex {
let start_index = self.statements_before_block[block];
PointIndex::new(start_index)
}
#[inline]
pub fn to_block_start(&self, index: PointIndex) -> PointIndex {
PointIndex::new(self.statements_before_block[self.basic_blocks[index]])
}
#[inline]
pub fn to_location(&self, index: PointIndex) -> Location {
assert!(index.index() < self.num_points);
let block = self.basic_blocks[index];
let start_index = self.statements_before_block[block];
let statement_index = index.index() - start_index;
Location { block, statement_index }
}
#[inline]
pub fn point_in_range(&self, index: PointIndex) -> bool {
index.index() < self.num_points
}
}
rustc_index::newtype_index! {
#[orderable]
#[debug_format = "PointIndex({})"]
pub struct PointIndex {}
}
pub fn save_as_intervals<'tcx, N, R>(
elements: &DenseLocationMap,
body: &mir::Body<'tcx>,
mut results: R,
) -> SparseIntervalMatrix<N, PointIndex>
where
N: Idx,
R: ResultsVisitable<'tcx, Domain = BitSet<N>>,
{
let values = SparseIntervalMatrix::new(elements.num_points());
let mut visitor = Visitor { elements, values };
visit_results(
body,
body.basic_blocks.reverse_postorder().iter().copied(),
&mut results,
&mut visitor,
);
visitor.values
}
struct Visitor<'a, N: Idx> {
elements: &'a DenseLocationMap,
values: SparseIntervalMatrix<N, PointIndex>,
}
impl<'mir, 'tcx, R, N> ResultsVisitor<'mir, 'tcx, R> for Visitor<'_, N>
where
N: Idx,
{
type Domain = BitSet<N>;
fn visit_statement_after_primary_effect(
&mut self,
_results: &mut R,
state: &Self::Domain,
_statement: &'mir mir::Statement<'tcx>,
location: Location,
) {
let point = self.elements.point_from_location(location);
state.iter().for_each(|node| {
self.values.insert(node, point);
});
}
fn visit_terminator_after_primary_effect(
&mut self,
_results: &mut R,
state: &Self::Domain,
_terminator: &'mir mir::Terminator<'tcx>,
location: Location,
) {
let point = self.elements.point_from_location(location);
state.iter().for_each(|node| {
self.values.insert(node, point);
});
}
}