mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

return default UniverseInfo cause in RegionInferenceContext

Browse Source 
Query canonicalization can create local super-universes without causes,
creating ICEs when accessed during diagnostics.
This commit is contained in:
Rémy Rakic 2023-08-30 13:51:09 +00:00
parent 7659abc63d
commit a725436c29
1 changed files with 8 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
compiler/rustc_borrowck/src/region_infer/mod.rs
View File

@ -2249,7 +2249,14 @@ pub(crate) fn best_blame_constraint(
}
pub(crate) fn universe_info(&self, universe: ty::UniverseIndex) -> UniverseInfo<'tcx> {
self.universe_causes[&universe].clone()
// Query canonicalization can create local superuniverses (for example in
// `InferCtx::query_response_substitution_guess`), but they don't have an associated
// `UniverseInfo` explaining why they were created.
// This can cause ICEs if these causes are accessed in diagnostics, for example in issue
// #114907 where this happens via liveness and dropck outlives results.
// Therefore, we return a default value in case that happens, which should at worst emit a
// suboptimal error, instead of the ICE.
self.universe_causes.get(&universe).cloned().unwrap_or_else(|| UniverseInfo::other())
}
/// Tries to find the terminator of the loop in which the region 'r' resides.