diff options
| -rw-r--r-- | compiler/rustc_hir_analysis/src/coherence/mod.rs | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/compiler/rustc_hir_analysis/src/coherence/mod.rs b/compiler/rustc_hir_analysis/src/coherence/mod.rs index 8cf1f2c9407..ef3a9f6cbd1 100644 --- a/compiler/rustc_hir_analysis/src/coherence/mod.rs +++ b/compiler/rustc_hir_analysis/src/coherence/mod.rs @@ -120,11 +120,13 @@ pub fn provide(providers: &mut Providers) { } fn coherent_trait(tcx: TyCtxt<'_>, def_id: DefId) -> Result<(), ErrorGuaranteed> { + // If there are no impls for the trait, then "all impls" are trivially coherent and we won't check anything + // anyway. Thus we bail out even before the specialization graph, avoiding the dep_graph edge. + let Some(impls) = tcx.all_local_trait_impls(()).get(&def_id) else { return Ok(()) }; // Trigger building the specialization graph for the trait. This will detect and report any // overlap errors. let mut res = tcx.ensure().specialization_graph_of(def_id); - let impls = tcx.hir().trait_impls(def_id); for &impl_def_id in impls { let trait_ref = tcx.impl_trait_ref(impl_def_id).unwrap().instantiate_identity(); |