Slightly more readable NLL/constraint graph dumps

This commit is contained in:
Amanda Stjerna 2024-04-11 16:56:45 +02:00
parent b14d8b2ef2
commit 800c50608c
4 changed files with 43 additions and 6 deletions

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@ -6,7 +6,38 @@ use std::borrow::Cow;
use std::io::{self, Write};
use super::*;
use itertools::Itertools;
use rustc_graphviz as dot;
use rustc_middle::ty::UniverseIndex;
fn render_outlives_constraint(constraint: &OutlivesConstraint<'_>) -> String {
match constraint.locations {
Locations::All(_) => "All(...)".to_string(),
Locations::Single(loc) => format!("{loc:?}"),
}
}
fn render_universe(u: UniverseIndex) -> String {
if u.is_root() {
return "".to_string();
}
format!("/{:?}", u)
}
fn render_region_vid(rvid: RegionVid, regioncx: &RegionInferenceContext<'_>) -> String {
let universe_str = render_universe(regioncx.region_definition(rvid).universe);
let external_name_str = if let Some(external_name) =
regioncx.region_definition(rvid).external_name.and_then(|e| e.get_name())
{
format!(" ({external_name})")
} else {
"".to_string()
};
format!("{:?}{universe_str}{external_name_str}", rvid)
}
impl<'tcx> RegionInferenceContext<'tcx> {
/// Write out the region constraint graph.
@ -46,10 +77,10 @@ impl<'a, 'this, 'tcx> dot::Labeller<'this> for RawConstraints<'a, 'tcx> {
Some(dot::LabelText::LabelStr(Cow::Borrowed("box")))
}
fn node_label(&'this self, n: &RegionVid) -> dot::LabelText<'this> {
dot::LabelText::LabelStr(format!("{n:?}").into())
dot::LabelText::LabelStr(render_region_vid(*n, self.regioncx).into())
}
fn edge_label(&'this self, e: &OutlivesConstraint<'tcx>) -> dot::LabelText<'this> {
dot::LabelText::LabelStr(format!("{:?}", e.locations).into())
dot::LabelText::LabelStr(render_outlives_constraint(e).into())
}
}
@ -96,8 +127,9 @@ impl<'a, 'this, 'tcx> dot::Labeller<'this> for SccConstraints<'a, 'tcx> {
Some(dot::LabelText::LabelStr(Cow::Borrowed("box")))
}
fn node_label(&'this self, n: &ConstraintSccIndex) -> dot::LabelText<'this> {
let nodes = &self.nodes_per_scc[*n];
dot::LabelText::LabelStr(format!("{n:?} = {nodes:?}").into())
let nodes_str =
self.nodes_per_scc[*n].iter().map(|n| render_region_vid(*n, self.regioncx)).join(", ");
dot::LabelText::LabelStr(format!("SCC({n}) = {{{nodes_str}}}", n = n.as_usize()).into())
}
}

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@ -1562,7 +1562,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
// Because this free region must be in the ROOT universe, we
// know it cannot contain any bound universes.
assert!(self.scc_universes[longer_fr_scc] == ty::UniverseIndex::ROOT);
assert!(self.scc_universes[longer_fr_scc].is_root());
debug_assert!(self.scc_values.placeholders_contained_in(longer_fr_scc).next().is_none());
// Only check all of the relations for the main representative of each

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@ -213,7 +213,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
let scc = self.constraint_sccs.scc(vid);
// Special handling of higher-ranked regions.
if self.scc_universes[scc] != ty::UniverseIndex::ROOT {
if !self.scc_universes[scc].is_root() {
match self.scc_values.placeholders_contained_in(scc).enumerate().last() {
// If the region contains a single placeholder then they're equal.
Some((0, placeholder)) => {

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@ -346,6 +346,11 @@ impl UniverseIndex {
pub fn cannot_name(self, other: UniverseIndex) -> bool {
self < other
}
/// Returns `true` if `self` is the root universe, otherwise false.
pub fn is_root(self) -> bool {
self == Self::ROOT
}
}
impl Default for UniverseIndex {