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Delay a bug when encountering an impl with unconstrained generics in codegen_select

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This commit is contained in:
Michael Goulet 2024-11-23 05:24:39 +00:00
parent f5be3ca1e3
commit 50fb40a987
4 changed files with 44 additions and 24 deletions
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21
compiler/rustc_traits/src/codegen.rs
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@ -74,12 +74,21 @@ pub(crate) fn codegen_select_candidate<'tcx>(
}
let impl_source = infcx.resolve_vars_if_possible(impl_source);
let impl_source = infcx.tcx.erase_regions(impl_source);
if impl_source.has_infer() {
// Unused lifetimes on an impl get replaced with inference vars, but never resolved,
// causing the return value of a query to contain inference vars. We do not have a concept
// for this and will in fact ICE in stable hashing of the return value. So bail out instead.
infcx.tcx.dcx().has_errors().unwrap();
let impl_source = tcx.erase_regions(impl_source);
if impl_source.has_non_region_infer() {
// Unused generic types or consts on an impl get replaced with inference vars,
// but never resolved, causing the return value of a query to contain inference
// vars. We do not have a concept for this and will in fact ICE in stable hashing
// of the return value. So bail out instead.
match impl_source {
ImplSource::UserDefined(impl_) => {
tcx.dcx().span_delayed_bug(
tcx.def_span(impl_.impl_def_id),
"this impl has unconstrained generic parameters",
);
}
_ => unreachable!(),
}
return Err(CodegenObligationError::FulfillmentError);
}