Module rustc_hir_typeck::generator_interior::drop_ranges

Drop range analysis finds the portions of the tree where a value is guaranteed to be dropped (i.e. moved, uninitialized, etc.). This is used to exclude the types of those values from the generator type. See InteriorVisitor::record for where the results of this analysis are used.

There are three phases to this analysis:

1. Use ExprUseVisitor to identify the interesting values that are consumed and borrowed.
2. Use DropRangeVisitor to find where the interesting values are dropped or reinitialized, and also build a control flow graph.
3. Use DropRanges::propagate_to_fixpoint to flow the dropped/reinitialized information through the CFG and find the exact points where we know a value is definitely dropped.

The end result is a data structure that maps the post-order index of each node in the HIR tree to a set of values that are known to be dropped at that location.

Modules

• cfg_build 🔒
• cfg_propagate 🔒
• cfg_visualize 🔒
  Implementation of GraphWalk for DropRanges so we can visualize the control flow graph when needed for debugging.
• record_consumed_borrow 🔒

Structs

• DropRanges
• DropRangesBuilder 🔒
  Tracks information needed to compute drop ranges.
• NodeInfo 🔒
• PostOrderId
• TrackedValueIndex

Enums

• TrackedValue 🔒
  Identifies a value whose drop state we need to track.
• TrackedValueConversionError 🔒
  Represents a reason why we might not be able to convert a HirId or Place into a tracked value.

Functions

• compute_drop_ranges
• for_each_consumable 🔒
  Applies f to consumable node in the HIR subtree pointed to by place.