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Tighten span when suggesting lifetime on path
1 parent 51e8031 commit e37d012

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5 files changed

+89
-7
lines changed

5 files changed

+89
-7
lines changed

compiler/rustc_ast_lowering/src/path.rs

+3-1
Original file line numberDiff line numberDiff line change
@@ -277,7 +277,9 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
277277
// See rustc_resolve::late::lifetimes::LifetimeContext::add_missing_lifetime_specifiers_label
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let elided_lifetime_span = if generic_args.span.is_empty() {
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// If there are no brackets, use the identifier span.
280-
path_span
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// HACK: we use find_ancestor_inside to properly suggest elided spans in paths
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// originating from macros, since the segment's span might be from a macro arg.
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segment.ident.span.find_ancestor_inside(path_span).unwrap_or(path_span)
281283
} else if generic_args.is_empty() {
282284
// If there are brackets, but not generic arguments, then use the opening bracket
283285
generic_args.span.with_hi(generic_args.span.lo() + BytePos(1))

compiler/rustc_resolve/src/late/diagnostics.rs

+6-3
Original file line numberDiff line numberDiff line change
@@ -2115,10 +2115,13 @@ impl<'tcx> LifetimeContext<'_, 'tcx> {
21152115
let spans_suggs: Vec<_> = formatters
21162116
.into_iter()
21172117
.zip(spans_with_counts.iter())
2118-
.filter_map(|(fmt, (span, _))| {
2119-
if let Some(formatter) = fmt { Some((formatter, span)) } else { None }
2118+
.filter_map(|(formatter, (span, _))| {
2119+
if let Some(formatter) = formatter {
2120+
Some((*span, formatter(name)))
2121+
} else {
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None
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}
21202124
})
2121-
.map(|(formatter, span)| (*span, formatter(name)))
21222125
.collect();
21232126
if spans_suggs.is_empty() {
21242127
// If all the spans come from macros, we cannot extract snippets and then
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,34 @@
1+
#![feature(generic_associated_types)]
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#![allow(unused)]
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trait Trait<'a> {
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type Foo;
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type Bar<'b>
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//~^ NOTE associated type defined here, with 1 lifetime parameter
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//~| NOTE
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where
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Self: 'b;
12+
}
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struct Impl<'a>(&'a ());
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impl<'a> Trait<'a> for Impl<'a> {
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type Foo = &'a ();
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type Bar<'b> = &'b ();
19+
}
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type A<'a> = Impl<'a>;
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type B<'a> = <A<'a> as Trait>::Foo;
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//~^ ERROR missing lifetime specifier
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//~| NOTE expected named lifetime parameter
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type C<'a, 'b> = <A<'a> as Trait>::Bar;
28+
//~^ ERROR missing lifetime specifier
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//~| ERROR missing generics for associated type
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//~| NOTE expected named lifetime parameter
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//~| NOTE these named lifetimes are available to use
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//~| NOTE expected 1 lifetime argument
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34+
fn main() {}
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,43 @@
1+
error[E0106]: missing lifetime specifier
2+
--> $DIR/missing-lifetime-in-alias.rs:23:24
3+
|
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LL | type B<'a> = <A<'a> as Trait>::Foo;
5+
| ^^^^^ expected named lifetime parameter
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|
7+
help: consider using the `'a` lifetime
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|
9+
LL | type B<'a> = <A<'a> as Trait<'a>>::Foo;
10+
| ~~~~~~~~~
11+
12+
error[E0106]: missing lifetime specifier
13+
--> $DIR/missing-lifetime-in-alias.rs:27:28
14+
|
15+
LL | type C<'a, 'b> = <A<'a> as Trait>::Bar;
16+
| ^^^^^ expected named lifetime parameter
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|
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note: these named lifetimes are available to use
19+
--> $DIR/missing-lifetime-in-alias.rs:27:8
20+
|
21+
LL | type C<'a, 'b> = <A<'a> as Trait>::Bar;
22+
| ^^ ^^
23+
24+
error[E0107]: missing generics for associated type `Trait::Bar`
25+
--> $DIR/missing-lifetime-in-alias.rs:27:36
26+
|
27+
LL | type C<'a, 'b> = <A<'a> as Trait>::Bar;
28+
| ^^^ expected 1 lifetime argument
29+
|
30+
note: associated type defined here, with 1 lifetime parameter: `'b`
31+
--> $DIR/missing-lifetime-in-alias.rs:7:10
32+
|
33+
LL | type Bar<'b>
34+
| ^^^ --
35+
help: add missing lifetime argument
36+
|
37+
LL | type C<'a, 'b> = <A<'a> as Trait>::Bar<'a>;
38+
| ~~~~~~~
39+
40+
error: aborting due to 3 previous errors
41+
42+
Some errors have detailed explanations: E0106, E0107.
43+
For more information about an error, try `rustc --explain E0106`.

src/test/ui/lint/reasons.stderr

+3-3
Original file line numberDiff line numberDiff line change
@@ -1,8 +1,8 @@
11
warning: hidden lifetime parameters in types are deprecated
2-
--> $DIR/reasons.rs:20:29
2+
--> $DIR/reasons.rs:20:34
33
|
44
LL | fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
5-
| ^^^^^^^^^^^^^^ expected named lifetime parameter
5+
| ^^^^^^^^^ expected named lifetime parameter
66
|
77
= note: explicit anonymous lifetimes aid reasoning about ownership
88
note: the lint level is defined here
@@ -13,7 +13,7 @@ LL | #![warn(elided_lifetimes_in_paths,
1313
help: consider using the `'_` lifetime
1414
|
1515
LL | fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
16-
| ~~~~~~~~~~~~~~~~~~
16+
| ~~~~~~~~~~~~~
1717

1818
warning: variable `Social_exchange_psychology` should have a snake case name
1919
--> $DIR/reasons.rs:30:9

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