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matthiaskrgrmatthiaskrgr
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Rollup merge of #120632 - trevyn:issue-109195, r=oli-obk
For E0223, suggest associated functions that are similar to the path e.g. for `String::from::utf8`, suggest `String::from_utf8` Closes #109195
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‎compiler/rustc_hir_analysis/src/astconv/errors.rs‎

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@@ -14,6 +14,7 @@ use rustc_errors::{
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use rustc_hir as hir;
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use rustc_hir::def_id::{DefId, LocalDefId};
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use rustc_infer::traits::FulfillmentError;
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use rustc_middle::query::Key;
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use rustc_middle::ty::{self, suggest_constraining_type_param, Ty, TyCtxt, TypeVisitableExt};
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use rustc_session::parse::feature_err;
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use rustc_span::edit_distance::find_best_match_for_name;
@@ -859,6 +860,56 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
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self.set_tainted_by_errors(err.emit());
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}
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/// On ambiguous associated type, look for an associated function whose name matches the
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/// extended path and, if found, emit an E0223 error with a structured suggestion.
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/// e.g. for `String::from::utf8`, suggest `String::from_utf8` (#109195)
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pub(crate) fn maybe_report_similar_assoc_fn(
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&self,
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span: Span,
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qself_ty: Ty<'tcx>,
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qself: &hir::Ty<'_>,
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) -> Result<(), ErrorGuaranteed> {
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let tcx = self.tcx();
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if let Some((_, node)) = tcx.hir().parent_iter(qself.hir_id).skip(1).next()
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&& let hir::Node::Expr(hir::Expr {
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kind:
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hir::ExprKind::Path(hir::QPath::TypeRelative(
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hir::Ty {
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kind:
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hir::TyKind::Path(hir::QPath::TypeRelative(
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_,
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hir::PathSegment { ident: ident2, .. },
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)),
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..
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},
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hir::PathSegment { ident: ident3, .. },
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)),
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..
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}) = node
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&& let Some(ty_def_id) = qself_ty.ty_def_id()
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&& let Ok([inherent_impl]) = tcx.inherent_impls(ty_def_id)
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&& let name = format!("{ident2}_{ident3}")
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&& let Some(ty::AssocItem { kind: ty::AssocKind::Fn, .. }) = tcx
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.associated_items(inherent_impl)
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.filter_by_name_unhygienic(Symbol::intern(&name))
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.next()
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{
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let reported =
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struct_span_code_err!(tcx.dcx(), span, E0223, "ambiguous associated type")
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.with_span_suggestion_verbose(
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ident2.span.to(ident3.span),
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format!("there is an associated function with a similar name: `{name}`"),
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name,
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Applicability::MaybeIncorrect,
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)
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.emit();
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self.set_tainted_by_errors(reported);
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Err(reported)
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} else {
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Ok(())
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}
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}
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}
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/// Emits an error regarding forbidden type binding associations

‎compiler/rustc_hir_analysis/src/astconv/mod.rs‎

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@@ -1373,6 +1373,8 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
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)
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.emit() // Already reported in an earlier stage.
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} else {
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self.maybe_report_similar_assoc_fn(span, qself_ty, qself)?;
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let traits: Vec<_> =
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self.probe_traits_that_match_assoc_ty(qself_ty, assoc_ident);
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‎tests/ui/suggestions/issue-109195.rs‎

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fn main() {
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String::from::utf8;
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//~^ ERROR ambiguous associated type [E0223]
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//~| HELP there is an associated function with a similar name: `from_utf8`
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String::from::utf8();
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//~^ ERROR ambiguous associated type [E0223]
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//~| HELP there is an associated function with a similar name: `from_utf8`
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String::from::utf16();
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//~^ ERROR ambiguous associated type [E0223]
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//~| HELP there is an associated function with a similar name: `from_utf16`
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String::from::method_that_doesnt_exist();
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//~^ ERROR ambiguous associated type [E0223]
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//~| HELP if there were a trait named `Example` with associated type `from`
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str::from::utf8();
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//~^ ERROR ambiguous associated type [E0223]
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//~| HELP if there were a trait named `Example` with associated type `from`
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str::from::utf8_mut();
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//~^ ERROR ambiguous associated type [E0223]
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//~| HELP if there were a trait named `Example` with associated type `from`
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}

‎tests/ui/suggestions/issue-109195.stderr‎

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error[E0223]: ambiguous associated type
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--> $DIR/issue-109195.rs:2:5
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|
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LL | String::from::utf8;
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| ^^^^^^^^^^^^
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|
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help: there is an associated function with a similar name: `from_utf8`
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|
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LL | String::from_utf8;
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| ~~~~~~~~~
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error[E0223]: ambiguous associated type
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--> $DIR/issue-109195.rs:5:5
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|
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LL | String::from::utf8();
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| ^^^^^^^^^^^^
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|
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help: there is an associated function with a similar name: `from_utf8`
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|
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LL | String::from_utf8();
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| ~~~~~~~~~
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error[E0223]: ambiguous associated type
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--> $DIR/issue-109195.rs:8:5
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|
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LL | String::from::utf16();
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| ^^^^^^^^^^^^
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|
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help: there is an associated function with a similar name: `from_utf16`
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|
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LL | String::from_utf16();
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| ~~~~~~~~~~
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error[E0223]: ambiguous associated type
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--> $DIR/issue-109195.rs:11:5
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|
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LL | String::from::method_that_doesnt_exist();
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| ^^^^^^^^^^^^
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|
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help: if there were a trait named `Example` with associated type `from` implemented for `String`, you could use the fully-qualified path
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|
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LL | <String as Example>::from::method_that_doesnt_exist();
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| ~~~~~~~~~~~~~~~~~~~~~~~~~
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error[E0223]: ambiguous associated type
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--> $DIR/issue-109195.rs:14:5
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|
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LL | str::from::utf8();
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| ^^^^^^^^^
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|
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help: if there were a trait named `Example` with associated type `from` implemented for `str`, you could use the fully-qualified path
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|
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LL | <str as Example>::from::utf8();
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| ~~~~~~~~~~~~~~~~~~~~~~
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error[E0223]: ambiguous associated type
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--> $DIR/issue-109195.rs:17:5
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|
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LL | str::from::utf8_mut();
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| ^^^^^^^^^
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|
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help: if there were a trait named `Example` with associated type `from` implemented for `str`, you could use the fully-qualified path
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|
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LL | <str as Example>::from::utf8_mut();
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| ~~~~~~~~~~~~~~~~~~~~~~
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error: aborting due to 6 previous errors
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For more information about this error, try `rustc --explain E0223`.

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