Skip to content
This repository was archived by the owner on May 28, 2025. It is now read-only.

Commit b726bfb

Browse files
compiler-errorscompiler-errors
committed
allow referencing impl substs from rustc_on_unimplemented
1 parent e9ddb8f commit b726bfb

File tree

5 files changed

+59
-28
lines changed

5 files changed

+59
-28
lines changed

‎compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs‎

Lines changed: 1 addition & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -231,9 +231,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
231231
}
232232
});
233233

234-
if let Ok(Some(command)) =
235-
OnUnimplementedDirective::of_item(self.tcx, trait_ref.def_id, def_id)
236-
{
234+
if let Ok(Some(command)) = OnUnimplementedDirective::of_item(self.tcx, def_id) {
237235
command.evaluate(self.tcx, trait_ref, &flags)
238236
} else {
239237
OnUnimplementedNote::default()

‎compiler/rustc_trait_selection/src/traits/on_unimplemented.rs‎

Lines changed: 26 additions & 20 deletions
Original file line numberDiff line numberDiff line change
@@ -54,7 +54,7 @@ fn parse_error(
5454
impl<'tcx> OnUnimplementedDirective {
5555
fn parse(
5656
tcx: TyCtxt<'tcx>,
57-
trait_def_id: DefId,
57+
item_def_id: DefId,
5858
items: &[NestedMetaItem],
5959
span: Span,
6060
is_root: bool,
@@ -63,7 +63,7 @@ impl<'tcx> OnUnimplementedDirective {
6363
let mut item_iter = items.iter();
6464

6565
let parse_value = |value_str| {
66-
OnUnimplementedFormatString::try_parse(tcx, trait_def_id, value_str, span).map(Some)
66+
OnUnimplementedFormatString::try_parse(tcx, item_def_id, value_str, span).map(Some)
6767
};
6868

6969
let condition = if is_root {
@@ -135,7 +135,7 @@ impl<'tcx> OnUnimplementedDirective {
135135
{
136136
if let Some(items) = item.meta_item_list() {
137137
if let Ok(subcommand) =
138-
Self::parse(tcx, trait_def_id, &items, item.span(), false)
138+
Self::parse(tcx, item_def_id, &items, item.span(), false)
139139
{
140140
subcommands.push(subcommand);
141141
} else {
@@ -178,27 +178,23 @@ impl<'tcx> OnUnimplementedDirective {
178178
}
179179
}
180180

181-
pub fn of_item(
182-
tcx: TyCtxt<'tcx>,
183-
trait_def_id: DefId,
184-
impl_def_id: DefId,
185-
) -> Result<Option<Self>, ErrorGuaranteed> {
186-
let attrs = tcx.get_attrs(impl_def_id);
181+
pub fn of_item(tcx: TyCtxt<'tcx>, item_def_id: DefId) -> Result<Option<Self>, ErrorGuaranteed> {
182+
let attrs = tcx.get_attrs(item_def_id);
187183

188184
let Some(attr) = tcx.sess.find_by_name(&attrs, sym::rustc_on_unimplemented) else {
189185
return Ok(None);
190186
};
191187

192188
let result = if let Some(items) = attr.meta_item_list() {
193-
Self::parse(tcx, trait_def_id, &items, attr.span, true).map(Some)
189+
Self::parse(tcx, item_def_id, &items, attr.span, true).map(Some)
194190
} else if let Some(value) = attr.value_str() {
195191
Ok(Some(OnUnimplementedDirective {
196192
condition: None,
197193
message: None,
198194
subcommands: vec![],
199195
label: Some(OnUnimplementedFormatString::try_parse(
200196
tcx,
201-
trait_def_id,
197+
item_def_id,
202198
value,
203199
attr.span,
204200
)?),
@@ -209,7 +205,7 @@ impl<'tcx> OnUnimplementedDirective {
209205
} else {
210206
return Err(ErrorGuaranteed);
211207
};
212-
debug!("of_item({:?}/{:?}) = {:?}", trait_def_id, impl_def_id, result);
208+
debug!("of_item({:?}) = {:?}", item_def_id, result);
213209
result
214210
}
215211

@@ -280,23 +276,29 @@ impl<'tcx> OnUnimplementedDirective {
280276
impl<'tcx> OnUnimplementedFormatString {
281277
fn try_parse(
282278
tcx: TyCtxt<'tcx>,
283-
trait_def_id: DefId,
279+
item_def_id: DefId,
284280
from: Symbol,
285281
err_sp: Span,
286282
) -> Result<Self, ErrorGuaranteed> {
287283
let result = OnUnimplementedFormatString(from);
288-
result.verify(tcx, trait_def_id, err_sp)?;
284+
result.verify(tcx, item_def_id, err_sp)?;
289285
Ok(result)
290286
}
291287

292288
fn verify(
293289
&self,
294290
tcx: TyCtxt<'tcx>,
295-
trait_def_id: DefId,
291+
item_def_id: DefId,
296292
span: Span,
297293
) -> Result<(), ErrorGuaranteed> {
298-
let name = tcx.item_name(trait_def_id);
299-
let generics = tcx.generics_of(trait_def_id);
294+
let trait_def_id = if tcx.is_trait(item_def_id) {
295+
item_def_id
296+
} else {
297+
tcx.trait_id_of_impl(item_def_id)
298+
.expect("expected `on_unimplemented` to correspond to a trait")
299+
};
300+
let trait_name = tcx.item_name(trait_def_id);
301+
let generics = tcx.generics_of(item_def_id);
300302
let s = self.0.as_str();
301303
let parser = Parser::new(s, None, None, false, ParseMode::Format);
302304
let mut result = Ok(());
@@ -307,7 +309,7 @@ impl<'tcx> OnUnimplementedFormatString {
307309
// `{Self}` is allowed
308310
Position::ArgumentNamed(s, _) if s == kw::SelfUpper => (),
309311
// `{ThisTraitsName}` is allowed
310-
Position::ArgumentNamed(s, _) if s == name => (),
312+
Position::ArgumentNamed(s, _) if s == trait_name => (),
311313
// `{from_method}` is allowed
312314
Position::ArgumentNamed(s, _) if s == sym::from_method => (),
313315
// `{from_desugaring}` is allowed
@@ -329,9 +331,13 @@ impl<'tcx> OnUnimplementedFormatString {
329331
tcx.sess,
330332
span,
331333
E0230,
332-
"there is no parameter `{}` on trait `{}`",
334+
"there is no parameter `{}` on {}",
333335
s,
334-
name
336+
if trait_def_id == item_def_id {
337+
format!("trait `{}`", trait_name)
338+
} else {
339+
"impl".to_string()
340+
}
335341
)
336342
.emit();
337343
result = Err(ErrorGuaranteed);

‎compiler/rustc_typeck/src/check/check.rs‎

Lines changed: 4 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -742,12 +742,11 @@ pub fn check_item_type<'tcx>(tcx: TyCtxt<'tcx>, it: &'tcx hir::Item<'tcx>) {
742742
impl_trait_ref,
743743
&impl_.items,
744744
);
745-
let trait_def_id = impl_trait_ref.def_id;
746-
check_on_unimplemented(tcx, trait_def_id, it);
745+
check_on_unimplemented(tcx, it);
747746
}
748747
}
749748
hir::ItemKind::Trait(_, _, _, _, ref items) => {
750-
check_on_unimplemented(tcx, it.def_id.to_def_id(), it);
749+
check_on_unimplemented(tcx, it);
751750

752751
for item in items.iter() {
753752
let item = tcx.hir().trait_item(item.id);
@@ -857,9 +856,9 @@ pub fn check_item_type<'tcx>(tcx: TyCtxt<'tcx>, it: &'tcx hir::Item<'tcx>) {
857856
}
858857
}
859858

860-
pub(super) fn check_on_unimplemented(tcx: TyCtxt<'_>, trait_def_id: DefId, item: &hir::Item<'_>) {
859+
pub(super) fn check_on_unimplemented(tcx: TyCtxt<'_>, item: &hir::Item<'_>) {
861860
// an error would be reported if this fails.
862-
let _ = traits::OnUnimplementedDirective::of_item(tcx, trait_def_id, item.def_id.to_def_id());
861+
let _ = traits::OnUnimplementedDirective::of_item(tcx, item.def_id.to_def_id());
863862
}
864863

865864
pub(super) fn check_specialization_validity<'tcx>(

‎src/test/ui/on-unimplemented/impl-substs.rs‎

Lines changed: 15 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,15 @@
1+
#![feature(rustc_attrs)]
2+
3+
trait Foo<A> {
4+
fn foo(self);
5+
}
6+
7+
#[rustc_on_unimplemented = "an impl did not match: {A} {B} {C}"]
8+
impl<A, B, C> Foo<A> for (A, B, C) {
9+
fn foo(self) {}
10+
}
11+
12+
fn main() {
13+
Foo::<usize>::foo((1i32, 1i32, 1i32));
14+
//~^ ERROR the trait bound `(i32, i32, i32): Foo<usize>` is not satisfied
15+
}

‎src/test/ui/on-unimplemented/impl-substs.stderr‎

Lines changed: 13 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,13 @@
1+
error[E0277]: the trait bound `(i32, i32, i32): Foo<usize>` is not satisfied
2+
--> $DIR/impl-substs.rs:13:23
3+
|
4+
LL | Foo::<usize>::foo((1i32, 1i32, 1i32));
5+
| ----------------- ^^^^^^^^^^^^^^^^^^ an impl did not match: usize _ _
6+
| |
7+
| required by a bound introduced by this call
8+
|
9+
= help: the trait `Foo<usize>` is not implemented for `(i32, i32, i32)`
10+
11+
error: aborting due to previous error
12+
13+
For more information about this error, try `rustc --explain E0277`.

0 commit comments

Comments
 (0)