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,
    inner_values: IndexVec<PlaceIndex, Range<usize>>,
    inner_values_buffer: Vec<ValueIndex>,
}

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

inner_values: IndexVec<PlaceIndex, Range<usize>>

inner_values_buffer: Vec<ValueIndex>

Implementations

impl Map

pub fn new<'tcx>( tcx: TyCtxt<'tcx>, body: &Body<'tcx>, value_limit: Option<usize> ) -> Self

Returns a map that only tracks places whose type has scalar layout.

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 are scalars).

fn register<'tcx>( &mut self, tcx: TyCtxt<'tcx>, body: &Body<'tcx>, exclude: BitSet<Local>, value_limit: Option<usize> )

Register all non-excluded places that have scalar layout.

fn register_children<'tcx>( &mut self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>, place: PlaceIndex, ty: Ty<'tcx>, worklist: &mut VecDeque<(PlaceIndex, Option<TrackElem>, TrackElem, Ty<'tcx>)> )

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

Invariant: The projection must only contain trackable elements.

fn cache_preorder_invoke(&mut self, root: PlaceIndex)

Precompute the list of values inside root and store it inside as a slice within inner_values_buffer.

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_extra( &self, place: PlaceRef<'_>, extra: impl IntoIterator<Item = TrackElem> ) -> Option<PlaceIndex>

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

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

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

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

Locates the given place and applies Discriminant, if it exists in the tree.

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

Locates the given place and applies DerefLen, if it exists in the tree.

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

Iterate over all direct children.

fn for_each_aliasing_place( &self, place: PlaceRef<'_>, tail_elem: Option<TrackElem>, f: &mut impl FnMut(ValueIndex) )

Invoke a function on the given place and all places that may alias it.

In particular, when the given place has a variant downcast, we invoke the function on all the other variants.

tail_elem allows to support discriminants that are not a place in MIR, but that we track as such.

fn for_each_variant_sibling( &self, parent: PlaceIndex, preserved_child: Option<PlaceIndex>, f: &mut impl FnMut(ValueIndex) )

Invoke the given function on all the descendants of the given place, except one branch.

fn for_each_value_inside( &self, root: PlaceIndex, f: &mut impl FnMut(ValueIndex) )

Invoke a function on each value in the given place and all descendants.

pub fn for_each_projection_value<O>( &self, root: PlaceIndex, value: O, project: &mut impl FnMut(TrackElem, &O) -> Option<O>, f: &mut impl FnMut(PlaceIndex, &O) )

Invoke a function on each value in 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: 136 bytes