bjoernager/rust
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Rename assign_idx methods.

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This commit is contained in:
Camille GILLOT 2023-02-03 16:39:10 +00:00
parent 67a8c16fe2
commit df889c9821
2 changed files with 39 additions and 31 deletions
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55
compiler/rustc_mir_dataflow/src/value_analysis.rs
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@ -24,7 +24,7 @@
//! - The bottom state denotes uninitialized memory. Because we are only doing a sound approximation
//! of the actual execution, we can also use this state for places where access would be UB.
//!
//! - The assignment logic in `State::assign_place_idx` assumes that the places are non-overlapping,
//! - The assignment logic in `State::insert_place_idx` assumes that the places are non-overlapping,
//! or identical. Note that this refers to place expressions, not memory locations.
//!
//! - Currently, places that have their reference taken cannot be tracked. Although this would be
@ -470,6 +470,28 @@ impl<V: Clone + HasTop + HasBottom> State<V> {
self.flood_discr_with(place, map, V::top())
}
/// Low-level method that assigns to a place.
/// This does nothing if the place is not tracked.
///
/// The target place must have been flooded before calling this method.
pub fn insert_idx(&mut self, target: PlaceIndex, result: ValueOrPlace<V>, map: &Map) {
match result {
ValueOrPlace::Value(value) => self.insert_value_idx(target, value, map),
ValueOrPlace::Place(source) => self.insert_place_idx(target, source, map),
}
}
/// Low-level method that assigns a value to a place.
/// This does nothing if the place is not tracked.
///
/// The target place must have been flooded before calling this method.
pub fn insert_value_idx(&mut self, target: PlaceIndex, value: V, map: &Map) {
let StateData::Reachable(values) = &mut self.0 else { return };
if let Some(value_index) = map.places[target].value_index {
values[value_index] = value;
}
}
/// Copies `source` to `target`, including all tracked places beneath.
///
/// If `target` contains a place that is not contained in `source`, it will be overwritten with
@ -477,52 +499,39 @@ impl<V: Clone + HasTop + HasBottom> State<V> {
/// places that are non-overlapping or identical.
///
/// The target place must have been flooded before calling this method.
fn assign_place_idx(&mut self, target: PlaceIndex, source: PlaceIndex, map: &Map) {
fn insert_place_idx(&mut self, target: PlaceIndex, source: PlaceIndex, map: &Map) {
let StateData::Reachable(values) = &mut self.0 else { return };
// If both places are tracked, we copy the value to the target. If the target is tracked,
// but the source is not, we have to invalidate the value in target. If the target is not
// tracked, then we don't have to do anything.
// If both places are tracked, we copy the value to the target.
// If the target is tracked, but the source is not, we do nothing, as invalidation has
// already been performed.
if let Some(target_value) = map.places[target].value_index {
if let Some(source_value) = map.places[source].value_index {
values[target_value] = values[source_value].clone();
} else {
values[target_value] = V::top();
}
}
for target_child in map.children(target) {
// Try to find corresponding child and recurse. Reasoning is similar as above.
let projection = map.places[target_child].proj_elem.unwrap();
if let Some(source_child) = map.projections.get(&(source, projection)) {
self.assign_place_idx(target_child, *source_child, map);
self.insert_place_idx(target_child, *source_child, map);
}
}
}
/// Helper method to interpret `target = result`.
pub fn assign(&mut self, target: PlaceRef<'_>, result: ValueOrPlace<V>, map: &Map) {
self.flood(target, map);
if let Some(target) = map.find(target) {
self.assign_idx(target, result, map);
self.insert_idx(target, result, map);
}
}
/// Helper method for assignments to a discriminant.
pub fn assign_discr(&mut self, target: PlaceRef<'_>, result: ValueOrPlace<V>, map: &Map) {
self.flood_discr(target, map);
if let Some(target) = map.find_discr(target) {
self.assign_idx(target, result, map);
}
}
/// The target place must have been flooded before calling this method.
pub fn assign_idx(&mut self, target: PlaceIndex, result: ValueOrPlace<V>, map: &Map) {
match result {
ValueOrPlace::Value(value) => {
let StateData::Reachable(values) = &mut self.0 else { return };
if let Some(value_index) = map.places[target].value_index {
values[value_index] = value;
}
}
ValueOrPlace::Place(source) => self.assign_place_idx(target, source, map),
self.insert_idx(target, result, map);
}
}