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Don't move ?Trait bounds to param bounds if they're in where clauses

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This commit is contained in:
jackh726 2021-08-15 00:53:40 -04:00
parent 2eaf9fe364
commit f1f1d56d93
12 changed files with 103 additions and 82 deletions
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12
compiler/rustc_middle/src/ty/diagnostics.rs
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@ -2,7 +2,6 @@
use crate::ty::TyKind::*;
use crate::ty::{InferTy, TyCtxt, TyS};
use rustc_data_structures::fx::FxHashSet;
use rustc_errors::{Applicability, DiagnosticBuilder};
use rustc_hir as hir;
use rustc_hir::def_id::DefId;
@ -114,10 +113,8 @@ fn suggest_removing_unsized_bound(
def_id: Option<DefId>,
) {
// See if there's a `?Sized` bound that can be removed to suggest that.
// First look at the `where` clause because we can have `where T: ?Sized`, but that
// `?Sized` bound is *also* included in the `GenericParam` as a bound, which breaks
// the spans. Hence the somewhat involved logic that follows.
let mut where_unsized_bounds = FxHashSet::default();
// First look at the `where` clause because we can have `where T: ?Sized`,
// then look at params.
for (where_pos, predicate) in generics.where_clause.predicates.iter().enumerate() {
match predicate {
WherePredicate::BoundPredicate(WhereBoundPredicate {
@ -140,7 +137,6 @@ fn suggest_removing_unsized_bound(
}) if segment.ident.as_str() == param_name => {
for (pos, bound) in bounds.iter().enumerate() {
match bound {
hir::GenericBound::Unsized(_) => {}
hir::GenericBound::Trait(poly, hir::TraitBoundModifier::Maybe)
if poly.trait_ref.trait_def_id() == def_id => {}
_ => continue,
@ -173,7 +169,6 @@ fn suggest_removing_unsized_bound(
// ^^^^^^^^^
(_, pos, _, _) => bounds[pos - 1].span().shrink_to_hi().to(bound.span()),
};
where_unsized_bounds.insert(bound.span());
err.span_suggestion_verbose(
sp,
"consider removing the `?Sized` bound to make the \
@ -189,8 +184,7 @@ fn suggest_removing_unsized_bound(
for (pos, bound) in param.bounds.iter().enumerate() {
match bound {
hir::GenericBound::Trait(poly, hir::TraitBoundModifier::Maybe)
if poly.trait_ref.trait_def_id() == def_id
&& !where_unsized_bounds.contains(&bound.span()) =>
if poly.trait_ref.trait_def_id() == def_id =>
{
let sp = match (param.bounds.len(), pos) {
// T: ?Sized,