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mu001999mu001999
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Emits E0599 when meeting MyTrait::missing_method
1 parent bc88895 commit db64512

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11 files changed

+147
-47
lines changed

11 files changed

+147
-47
lines changed

‎compiler/rustc_errors/src/lib.rs

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -478,6 +478,7 @@ pub enum StashKey {
478478
/// FRU syntax
479479
MaybeFruTypo,
480480
CallAssocMethod,
481+
TraitMissingMethod,
481482
}
482483

483484
fn default_track_diagnostic(d: &mut Diagnostic, f: &mut dyn FnMut(&mut Diagnostic)) {

‎compiler/rustc_hir_analysis/src/astconv/mod.rs

Lines changed: 3 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -19,7 +19,7 @@ use rustc_ast::TraitObjectSyntax;
1919
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
2020
use rustc_errors::{
2121
struct_span_err, Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed, FatalError,
22-
MultiSpan,
22+
MultiSpan, StashKey,
2323
};
2424
use rustc_hir as hir;
2525
use rustc_hir::def::{CtorOf, DefKind, Namespace, Res};
@@ -38,7 +38,6 @@ use rustc_middle::ty::{self, Const, IsSuggestable, Ty, TyCtxt, TypeVisitableExt}
3838
use rustc_middle::ty::{DynKind, ToPredicate};
3939
use rustc_session::lint::builtin::{AMBIGUOUS_ASSOCIATED_ITEMS, BARE_TRAIT_OBJECTS};
4040
use rustc_span::edit_distance::find_best_match_for_name;
41-
use rustc_span::edition::Edition;
4241
use rustc_span::symbol::{kw, Ident, Symbol};
4342
use rustc_span::{sym, Span, DUMMY_SP};
4443
use rustc_target::spec::abi;
@@ -3718,7 +3717,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
37183717
));
37193718
}
37203719

3721-
if self_ty.span.edition() >= Edition::Edition2021 {
3720+
if self_ty.span.edition().rust_2021() {
37223721
let msg = "trait objects must include the `dyn` keyword";
37233722
let label = "add `dyn` keyword before this trait";
37243723
let mut diag =
@@ -3732,7 +3731,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
37323731
}
37333732
// check if the impl trait that we are considering is a impl of a local trait
37343733
self.maybe_lint_blanket_trait_impl(&self_ty, &mut diag);
3735-
diag.emit();
3734+
diag.stash(self_ty.span, StashKey::TraitMissingMethod);
37363735
} else {
37373736
let msg = "trait objects without an explicit `dyn` are deprecated";
37383737
tcx.struct_span_lint_hir(

‎compiler/rustc_hir_typeck/messages.ftl

Lines changed: 11 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -79,3 +79,14 @@ hir_typeck_arg_mismatch_indeterminate = argument type mismatch was detected, but
7979
hir_typeck_suggest_boxing_note = for more on the distinction between the stack and the heap, read https://doc.rust-lang.org/book/ch15-01-box.html, https://doc.rust-lang.org/rust-by-example/std/box.html, and https://doc.rust-lang.org/std/boxed/index.html
8080
8181
hir_typeck_suggest_boxing_when_appropriate = store this in the heap by calling `Box::new`
82+
83+
hir_typeck_no_associated_item = no {$item_kind} named `{$item_name}` found for {$ty_prefix} `{$ty_str}`{$trait_missing_method ->
84+
[true] {""}
85+
*[other] {" "}in the current scope
86+
}
87+
88+
hir_typeck_candidate_trait_note = `{$trait_name}` defines an item `{$item_name}`{$action_or_ty ->
89+
[NONE] {""}
90+
[implement] , perhaps you need to implement it
91+
*[other] , perhaps you need to restrict type parameter `{$action_or_ty}` with it
92+
}

‎compiler/rustc_hir_typeck/src/errors.rs

Lines changed: 24 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,6 @@
11
//! Errors emitted by `rustc_hir_typeck`.
2+
use std::borrow::Cow;
3+
24
use crate::fluent_generated as fluent;
35
use rustc_errors::{AddToDiagnostic, Applicability, Diagnostic, MultiSpan, SubdiagnosticMessage};
46
use rustc_macros::{Diagnostic, Subdiagnostic};
@@ -295,3 +297,25 @@ pub enum SuggestBoxing {
295297
end: Span,
296298
},
297299
}
300+
301+
#[derive(Diagnostic)]
302+
#[diag(hir_typeck_no_associated_item, code = "E0599")]
303+
pub struct NoAssociatedItem {
304+
#[primary_span]
305+
pub span: Span,
306+
pub item_kind: &'static str,
307+
pub item_name: Ident,
308+
pub ty_prefix: Cow<'static, str>,
309+
pub ty_str: String,
310+
pub trait_missing_method: bool,
311+
}
312+
313+
#[derive(Subdiagnostic)]
314+
#[note(hir_typeck_candidate_trait_note)]
315+
pub struct CandidateTraitNote {
316+
#[primary_span]
317+
pub span: Span,
318+
pub trait_name: String,
319+
pub item_name: Ident,
320+
pub action_or_ty: String,
321+
}

‎compiler/rustc_hir_typeck/src/expr.rs

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1245,6 +1245,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
12451245
error,
12461246
Some((rcvr, args)),
12471247
expected,
1248+
false,
12481249
) {
12491250
err.emit();
12501251
}

‎compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs

Lines changed: 24 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -4,7 +4,7 @@ use crate::rvalue_scopes;
44
use crate::{BreakableCtxt, Diverges, Expectation, FnCtxt, LocalTy, RawTy};
55
use rustc_data_structures::captures::Captures;
66
use rustc_data_structures::fx::FxHashSet;
7-
use rustc_errors::{Applicability, Diagnostic, ErrorGuaranteed, MultiSpan};
7+
use rustc_errors::{Applicability, Diagnostic, ErrorGuaranteed, MultiSpan, StashKey};
88
use rustc_hir as hir;
99
use rustc_hir::def::{CtorOf, DefKind, Res};
1010
use rustc_hir::def_id::DefId;
@@ -853,6 +853,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
853853
let item_name = item_segment.ident;
854854
let result = self
855855
.resolve_fully_qualified_call(span, item_name, ty.normalized, qself.span, hir_id)
856+
.and_then(|r| {
857+
// lint bare trait if the method is found in the trait
858+
if span.edition().rust_2021() && let Some(mut diag) = self.tcx.sess.diagnostic().steal_diagnostic(qself.span, StashKey::TraitMissingMethod) {
859+
diag.emit();
860+
}
861+
Ok(r)
862+
})
856863
.or_else(|error| {
857864
let guar = self
858865
.tcx
@@ -863,17 +870,30 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
863870
_ => Err(guar),
864871
};
865872

873+
let trait_missing_method =
874+
matches!(error, method::MethodError::NoMatch(_)) && ty.normalized.is_trait();
866875
// If we have a path like `MyTrait::missing_method`, then don't register
867876
// a WF obligation for `dyn MyTrait` when method lookup fails. Otherwise,
868877
// register a WF obligation so that we can detect any additional
869878
// errors in the self type.
870-
if !(matches!(error, method::MethodError::NoMatch(_)) && ty.normalized.is_trait()) {
879+
if !trait_missing_method {
871880
self.register_wf_obligation(
872881
ty.raw.into(),
873882
qself.span,
874883
traits::WellFormed(None),
875884
);
876885
}
886+
887+
// emit or cancel the diagnostic for bare traits
888+
if span.edition().rust_2021() && let Some(mut diag) = self.tcx.sess.diagnostic().steal_diagnostic(qself.span, StashKey::TraitMissingMethod) {
889+
if trait_missing_method {
890+
// cancel the diag for bare traits when meeting `MyTrait::missing_method`
891+
diag.cancel();
892+
} else {
893+
diag.emit();
894+
}
895+
}
896+
877897
if item_name.name != kw::Empty {
878898
if let Some(mut e) = self.report_method_error(
879899
span,
@@ -883,10 +903,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
883903
error,
884904
None,
885905
Expectation::NoExpectation,
906+
trait_missing_method && span.edition().rust_2021(), // emits missing method for trait only after edition 2021
886907
) {
887908
e.emit();
888909
}
889910
}
911+
890912
result
891913
});
892914

‎compiler/rustc_hir_typeck/src/method/suggest.rs

Lines changed: 55 additions & 30 deletions
Original file line numberDiff line numberDiff line change
@@ -2,6 +2,8 @@
22
//! found or is otherwise invalid.
33
44
use crate::errors;
5+
use crate::errors::CandidateTraitNote;
6+
use crate::errors::NoAssociatedItem;
57
use crate::Expectation;
68
use crate::FnCtxt;
79
use rustc_ast::ast::Mutability;
@@ -38,6 +40,7 @@ use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _
3840
use rustc_trait_selection::traits::{
3941
FulfillmentError, Obligation, ObligationCause, ObligationCauseCode,
4042
};
43+
use std::borrow::Cow;
4144

4245
use super::probe::{AutorefOrPtrAdjustment, IsSuggestion, Mode, ProbeScope};
4346
use super::{CandidateSource, MethodError, NoMatchData};
@@ -112,6 +115,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
112115
error: MethodError<'tcx>,
113116
args: Option<(&'tcx hir::Expr<'tcx>, &'tcx [hir::Expr<'tcx>])>,
114117
expected: Expectation<'tcx>,
118+
trait_missing_method: bool,
115119
) -> Option<DiagnosticBuilder<'_, ErrorGuaranteed>> {
116120
// Avoid suggestions when we don't know what's going on.
117121
if rcvr_ty.references_error() {
@@ -136,6 +140,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
136140
sugg_span,
137141
&mut no_match_data,
138142
expected,
143+
trait_missing_method,
139144
);
140145
}
141146

@@ -278,6 +283,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
278283
sugg_span: Span,
279284
no_match_data: &mut NoMatchData<'tcx>,
280285
expected: Expectation<'tcx>,
286+
trait_missing_method: bool,
281287
) -> Option<DiagnosticBuilder<'_, ErrorGuaranteed>> {
282288
let mode = no_match_data.mode;
283289
let tcx = self.tcx;
@@ -323,7 +329,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
323329
span = item_name.span;
324330

325331
// Don't show generic arguments when the method can't be found in any implementation (#81576).
326-
let mut ty_str_reported = ty_str.clone();
332+
let mut ty_str_reported = if trait_missing_method {
333+
ty_str.strip_prefix("dyn ").expect("Failed to remove the prefix dyn").to_owned()
334+
} else {
335+
ty_str.clone()
336+
};
337+
327338
if let ty::Adt(_, generics) = rcvr_ty.kind() {
328339
if generics.len() > 0 {
329340
let mut autoderef = self.autoderef(span, rcvr_ty);
@@ -355,25 +366,33 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
355366
{
356367
self.suggest_missing_writer(rcvr_ty, args)
357368
} else {
358-
struct_span_err!(
359-
tcx.sess,
369+
tcx.sess.create_err(NoAssociatedItem {
360370
span,
361-
E0599,
362-
"no {} named `{}` found for {} `{}` in the current scope",
363371
item_kind,
364372
item_name,
365-
rcvr_ty.prefix_string(self.tcx),
366-
ty_str_reported,
367-
)
373+
ty_prefix: if trait_missing_method {
374+
// FIXME(mu001999) E0599 maybe not suitable here because it is for types
375+
Cow::from("trait")
376+
} else {
377+
rcvr_ty.prefix_string(self.tcx)
378+
},
379+
ty_str: ty_str_reported,
380+
trait_missing_method,
381+
})
368382
};
369383
if tcx.sess.source_map().is_multiline(sugg_span) {
370384
err.span_label(sugg_span.with_hi(span.lo()), "");
371385
}
372-
let ty_str = if short_ty_str.len() < ty_str.len() && ty_str.len() > 10 {
386+
let mut ty_str = if short_ty_str.len() < ty_str.len() && ty_str.len() > 10 {
373387
short_ty_str
374388
} else {
375389
ty_str
376390
};
391+
if trait_missing_method {
392+
ty_str =
393+
ty_str.strip_prefix("dyn ").expect("Failed to remove the prefix dyn").to_owned();
394+
}
395+
377396
if let Some(file) = ty_file {
378397
err.note(format!("the full type name has been written to '{}'", file.display(),));
379398
}
@@ -1067,6 +1086,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
10671086
&static_candidates,
10681087
unsatisfied_bounds,
10691088
expected.only_has_type(self),
1089+
trait_missing_method,
10701090
);
10711091
}
10721092

@@ -2375,6 +2395,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
23752395
static_candidates: &[CandidateSource],
23762396
unsatisfied_bounds: bool,
23772397
return_type: Option<Ty<'tcx>>,
2398+
trait_missing_method: bool,
23782399
) {
23792400
let mut alt_rcvr_sugg = false;
23802401
if let (SelfSource::MethodCall(rcvr), false) = (source, unsatisfied_bounds) {
@@ -2598,11 +2619,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
25982619
},
25992620
_ => None,
26002621
};
2601-
err.help(if param_type.is_some() {
2602-
"items from traits can only be used if the type parameter is bounded by the trait"
2603-
} else {
2604-
"items from traits can only be used if the trait is implemented and in scope"
2605-
});
2622+
if !trait_missing_method {
2623+
err.help(if param_type.is_some() {
2624+
"items from traits can only be used if the type parameter is bounded by the trait"
2625+
} else {
2626+
"items from traits can only be used if the trait is implemented and in scope"
2627+
});
2628+
}
2629+
26062630
let candidates_len = candidates.len();
26072631
let message = |action| {
26082632
format!(
@@ -2736,27 +2760,28 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
27362760
(candidates, Vec::new())
27372761
};
27382762

2739-
let action = if let Some(param) = param_type {
2740-
format!("restrict type parameter `{}` with", param)
2741-
} else {
2742-
// FIXME: it might only need to be imported into scope, not implemented.
2743-
"implement".to_string()
2744-
};
27452763
match &potential_candidates[..] {
27462764
[] => {}
27472765
[trait_info] if trait_info.def_id.is_local() => {
2748-
err.span_note(
2749-
self.tcx.def_span(trait_info.def_id),
2750-
format!(
2751-
"`{}` defines an item `{}`, perhaps you need to {} it",
2752-
self.tcx.def_path_str(trait_info.def_id),
2753-
item_name,
2754-
action
2755-
),
2756-
);
2766+
err.subdiagnostic(CandidateTraitNote {
2767+
span: self.tcx.def_span(trait_info.def_id),
2768+
trait_name: self.tcx.def_path_str(trait_info.def_id),
2769+
item_name,
2770+
action_or_ty: if trait_missing_method {
2771+
"NONE".to_string()
2772+
} else {
2773+
param_type.map_or_else(
2774+
|| "implement".to_string(), // FIXME: it might only need to be imported into scope, not implemented.
2775+
ToString::to_string,
2776+
)
2777+
},
2778+
});
27572779
}
27582780
trait_infos => {
2759-
let mut msg = message(action);
2781+
let mut msg = message(param_type.map_or_else(
2782+
|| "implement".to_string(), // FIXME: it might only need to be imported into scope, not implemented.
2783+
|param| format!("restrict type parameter `{}` with", param),
2784+
));
27602785
for (i, trait_info) in trait_infos.iter().enumerate() {
27612786
msg.push_str(&format!(
27622787
"\ncandidate #{}: `{}`",

‎tests/ui/resolve/issue-111312.rs

Lines changed: 11 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,11 @@
1+
// edition: 2021
2+
3+
trait Has {
4+
fn has() {}
5+
}
6+
7+
trait HasNot {}
8+
9+
fn main() {
10+
HasNot::has(); //~ ERROR
11+
}

‎tests/ui/resolve/issue-111312.stderr

Lines changed: 15 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,15 @@
1+
error[E0599]: no function or associated item named `has` found for trait `HasNot`
2+
--> $DIR/issue-111312.rs:10:13
3+
|
4+
LL | HasNot::has();
5+
| ^^^ function or associated item not found in `HasNot`
6+
|
7+
note: `Has` defines an item `has`
8+
--> $DIR/issue-111312.rs:3:1
9+
|
10+
LL | trait Has {
11+
| ^^^^^^^^^
12+
13+
error: aborting due to previous error
14+
15+
For more information about this error, try `rustc --explain E0599`.

‎tests/ui/traits/issue-106072.rs

Lines changed: 0 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,4 @@
11
#[derive(Clone)] //~ trait objects must include the `dyn` keyword
2-
//~| trait objects must include the `dyn` keyword
32
struct Foo;
43
trait Foo {} //~ the name `Foo` is defined multiple times
54
fn main() {}

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