Struct rustc_mir_dataflow::value_analysis::Map

pub struct Map {
    locals: IndexVec<Local, Option<PlaceIndex>>,
    projections: FxHashMap<(PlaceIndex, TrackElem), PlaceIndex>,
    places: IndexVec<PlaceIndex, PlaceInfo>,
    value_count: usize,
}

Partial mapping from Place to PlaceIndex, where some places also have a ValueIndex.

This data structure essentially maintains a tree of places and their projections. Some additional bookkeeping is done, to speed up traversal over this tree:

• For iteration, every PlaceInfo contains an intrusive linked list of its children.
• To directly get the child for a specific projection, there is a projections map.

Fields

locals: IndexVec<Local, Option<PlaceIndex>>

projections: FxHashMap<(PlaceIndex, TrackElem), PlaceIndex>

places: IndexVec<PlaceIndex, PlaceInfo>

value_count: usize

Implementations

impl Map

fn new() -> Self

pub fn from_filter<'tcx>(
    tcx: TyCtxt<'tcx>,
    body: &Body<'tcx>,
    filter: impl FnMut(Ty<'tcx>) -> bool
) -> Self

Returns a map that only tracks places whose type passes the filter.

This is currently the only way to create a Map. The way in which the tracked places are chosen is an implementation detail and may not be relied upon (other than that their type passes the filter).

fn register_with_filter<'tcx>(
    &mut self,
    tcx: TyCtxt<'tcx>,
    body: &Body<'tcx>,
    filter: impl FnMut(Ty<'tcx>) -> bool,
    exclude: &IndexVec<Local, bool>
)

Register all non-excluded places that pass the filter.

fn register_with_filter_rec<'tcx>(
    &mut self,
    tcx: TyCtxt<'tcx>,
    local: Local,
    projection: &mut Vec<PlaceElem<'tcx>>,
    ty: Ty<'tcx>,
    filter: &mut impl FnMut(Ty<'tcx>) -> bool
)

Potentially register the (local, projection) place and its fields, recursively.

Invariant: The projection must only contain fields.

fn make_place<'tcx>(
    &mut self,
    local: Local,
    projection: &[PlaceElem<'tcx>]
) -> Result<PlaceIndex, ()>

Tries to add the place to the map, without allocating a value slot.

Can fail if the projection contains non-trackable elements.

pub fn tracked_places(&self) -> usize

Returns the number of tracked places, i.e., those for which a value can be stored.

pub fn apply(&self, place: PlaceIndex, elem: TrackElem) -> Option<PlaceIndex>

Applies a single projection element, yielding the corresponding child.

pub fn find(&self, place: PlaceRef<'_>) -> Option<PlaceIndex>

Locates the given place, if it exists in the tree.

pub fn children(
    &self,
    parent: PlaceIndex
) -> impl Iterator<Item = PlaceIndex> + '_

Iterate over all direct children.

pub fn preorder_invoke(&self, root: PlaceIndex, f: &mut impl FnMut(PlaceIndex))

Invoke a function on the given place and all descendants.

Trait Implementations

impl Debug for Map

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference’s “Type Layout” chapter for details on type layout guarantees.

Size: 88 bytes