diagnostics: add note when param-env shadows global impl #150424
Conversation
This comment has been minimized.
This comment has been minimized.
| let all_impls = | ||
| impls.blanket_impls().iter().chain(impls.non_blanket_impls().values().flatten()); | ||
|
|
||
| for &impl_def_id in all_impls { |
There was a problem hiding this comment.
use compute_applicable_impls_for_diagnostics instead of all_impls here
There was a problem hiding this comment.
and specialization_graph::assoc_def to get the DefId of the assoc item
| "the associated type `{}` is defined as `{}` in the implementation, \ | ||
| but the generic bound `{}` hides this definition", |
There was a problem hiding this comment.
cc @rust-lang/types unsure about this note. I think it's certainly useful. Ideally we'd link to some reference section or github issue explaining impl shadowing.
I think it's easiest to write a special github issue for this quickly explaining why this happens, what they can do about it, and how this may change in the future
There was a problem hiding this comment.
Im not sure a github issue is the best place but also I don't know where would be better... If something reference-like was t-types controlled then certainly there 🤔 github issue is probably good enough :)
There was a problem hiding this comment.
should I open a issue then ?
There was a problem hiding this comment.
going to do so myself as I have strong opinions on the way we frame this
This comment has been minimized.
This comment has been minimized.
22a4a6b to
f616235
Compare
|
@lcnr I made the suggested changes and CI is also green now . |
| let impl_trait_ref = tcx.impl_trait_ref(impl_def_id).instantiate(tcx, impl_substs); | ||
|
|
||
| let expected_trait_ref = alias.trait_ref(tcx); | ||
|
|
||
| if !self.infcx.can_eq(param_env, expected_trait_ref, impl_trait_ref) { | ||
| return false; | ||
| } |
There was a problem hiding this comment.
no need, handled by compute_applicable_impls_for_diagnostics
| let impl_trait_ref = tcx.impl_trait_ref(impl_def_id).instantiate(tcx, impl_substs); | |
| let expected_trait_ref = alias.trait_ref(tcx); | |
| if !self.infcx.can_eq(param_env, expected_trait_ref, impl_trait_ref) { | |
| return false; | |
| } |
This PR adds a diagnostics note when param-env shadows global impl as discussed in #149910
It adds a note explaining that the definition is hidden by the generic bound.
r?lcnr