Struct rustc_data_structures::obligation_forest::ObligationForest

pub struct ObligationForest<O: ForestObligation> { /* fields omitted */ }

Methods

impl<O: ForestObligation> ObligationForest<O>

pub fn dump_graphviz<P: AsRef<Path>>(&self, dir: P, description: &str)

Creates a graphviz representation of the obligation forest. Given a directory this will create files with name of the format <counter>_<description>.gv. The counter is global and is maintained internally.

Calling this will do nothing unless the environment variable DUMP_OBLIGATION_FOREST_GRAPHVIZ is defined.

A few post-processing that you might want to do make the forest easier to visualize:

• sed 's,std::[a-z]*::,,g' — Deletes the std::<package>:: prefix of paths.
• sed 's,"Binder(TraitPredicate(<\(.*\)>)) (\([^)]*\))","\1 (\2)",' — Transforms Binder(TraitPredicate(<predicate>)) into just <predicate>.

impl<O: ForestObligation> ObligationForest<O>

pub fn new() -> ObligationForest<O>

pub fn len(&self) -> usize

Returns the total number of nodes in the forest that have not yet been fully resolved.

pub fn register_obligation(&mut self, obligation: O)

Registers an obligation.

This CAN be done in a snapshot

pub fn to_errors<E: Clone>(&mut self, error: E) -> Vec<Error<O, E>>

Converts all remaining obligations to the given error.

This cannot be done during a snapshot.

pub fn map_pending_obligations<P, F>(&self, f: F) -> Vec<P> where
    F: Fn(&O) -> P, 

Returns the set of obligations that are in a pending state.

pub fn process_obligations<P>(
    &mut self,
    processor: &mut P,
    do_completed: DoCompleted
) -> Outcome<O, P::Error> where
    P: ObligationProcessor<Obligation = O>, 

Performs a pass through the obligation list. This must be called in a loop until outcome.stalled is false.

This cannot be unrolled (presently, at least).

Trait Implementations

impl<'a, O: ForestObligation + 'a> Labeller<'a> for &'a ObligationForest<O>

type Node = usize

type Edge = (usize, usize)

fn graph_id(&self) -> Id

Must return a DOT compatible identifier naming the graph.

fn node_id(&self, index: &Self::Node) -> Id

Maps n to a unique identifier with respect to self. The implementor is responsible for ensuring that the returned name is a valid DOT identifier.

fn node_label(&self, index: &Self::Node) -> LabelText

Maps n to a label that will be used in the rendered output. The label need not be unique, and may be the empty string; the default is just the output from node_id.

fn edge_label(&self, (_index_source, _index_target): &Self::Edge) -> LabelText

Maps e to a label that will be used in the rendered output. The label need not be unique, and may be the empty string; the default is in fact the empty string.

fn node_shape(&'a self, _node: &Self::Node) -> Option<LabelText<'a>>

Maps n to one of the [graphviz shape names][1]. If None is returned, no shape attribute is specified.

fn node_style(&'a self, _n: &Self::Node) -> Style

Maps n to a style that will be used in the rendered output.

fn edge_style(&'a self, _e: &Self::Edge) -> Style

Maps e to a style that will be used in the rendered output.

impl<'a, O: ForestObligation + 'a> GraphWalk<'a> for &'a ObligationForest<O>

type Node = usize

type Edge = (usize, usize)

fn nodes(&self) -> Nodes<Self::Node>

Returns all the nodes in this graph.

fn edges(&self) -> Edges<Self::Edge>

Returns all of the edges in this graph.

fn source(&self, (s, _): &Self::Edge) -> Self::Node

The source node for edge.

fn target(&self, (_, t): &Self::Edge) -> Self::Node

The target node for edge.