diff options
| -rw-r--r-- | compiler/rustc_trait_selection/src/solve/fulfill.rs | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/compiler/rustc_trait_selection/src/solve/fulfill.rs b/compiler/rustc_trait_selection/src/solve/fulfill.rs index e0b9380eca3..01bdae7435d 100644 --- a/compiler/rustc_trait_selection/src/solve/fulfill.rs +++ b/compiler/rustc_trait_selection/src/solve/fulfill.rs @@ -241,6 +241,17 @@ where match certainty { Certainty::Yes => { + // Goals may depend on structural identity. Region uniquification at the + // start of MIR borrowck may cause things to no longer be so, potentially + // causing an ICE. + // + // While we uniquify root goals in HIR this does not handle cases where + // regions are hidden inside of a type or const inference variable. + // + // FIXME(-Znext-solver): This does not handle inference variables hidden + // inside of an opaque type, e.g. if there's `Opaque = (?x, ?x)` in the + // storage, we can also rely on structural identity of `?x` even if we + // later uniquify it in MIR borrowck. if infcx.in_hir_typeck && obligation.has_non_region_infer() { infcx.push_hir_typeck_potentially_region_dependent_goal(obligation); } |