bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Rollup merge of #109641 - compiler-errors:dont-elaborate-non-obl, r=oli-obk

Browse source 
Don't elaborate non-obligations into obligations

It's suspicious to elaborate a `PolyTraitRef` or `Predicate` into an `Obligation`, since the former does not have a param-env associated with it, but the latter does. This is a footgun that, while not being misused *currently* in the compiler, easily could be misused by someone less familiar with the elaborator's inner workings.

This PR just changes the API -- ideally, the elaborator wouldn't even have to deal with obligations if we're not elaborating obligations, but that would require a bit more abstraction than I could be bothered with today.
This commit is contained in:
Matthias Krüger 2023-03-27 08:46:55 +02:00 • committed by GitHub
commit 6535e66fa5
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
20 changed files with 112 additions and 131 deletions
Download patch file Download diff file Expand all files Collapse all files

4
compiler/rustc_lint/src/unused.rs
View file

@ -258,11 +258,11 @@ impl<'tcx> LateLintPass<'tcx> for UnusedResults {
cx.tcx,
cx.tcx.explicit_item_bounds(def).iter().cloned(),
)
.find_map(|obligation| {
.find_map(|(pred, _span)| {
// We only look at the `DefId`, so it is safe to skip the binder here.
if let ty::PredicateKind::Clause(ty::Clause::Trait(
ref poly_trait_predicate,
)) = obligation.predicate.kind().skip_binder()
)) = pred.kind().skip_binder()
{
let def_id = poly_trait_predicate.trait_ref.def_id;