Tweak wording

Author: estebank

src/librustc_resolve/late/diagnostics.rs

@@ -1034,6 +1034,8 @@ impl<'tcx> LifetimeContext<'_, 'tcx> {
         lifetime_names: &FxHashSet<ast::Ident>,
         params: &[ElisionFailureInfo],
     ) {
+        let snippet = self.tcx.sess.source_map().span_to_snippet(span).ok();
+
         err.span_label(
             span,
             &format!(
@@ -1043,11 +1045,10 @@ impl<'tcx> LifetimeContext<'_, 'tcx> {
             ),
         );
 
-        let snippet = self.tcx.sess.source_map().span_to_snippet(span).ok();
         let suggest_existing = |err: &mut DiagnosticBuilder<'_>, sugg| {
             err.span_suggestion_verbose(
                 span,
-                "consider using the named lifetime",
+                &format!("consider using the `{}` lifetime", lifetime_names.iter().next().unwrap()),
                 sugg,
                 Applicability::MaybeIncorrect,
             );
@@ -1137,6 +1138,20 @@ impl<'tcx> LifetimeContext<'_, 'tcx> {
             (0, _, Some(snippet)) if !snippet.ends_with('>') && count == 1 => {
                 suggest_new(err, &format!("{}<'a>", snippet));
             }
+            (n, ..) if n > 1 => {
+                let spans: Vec<Span> = lifetime_names.iter().map(|lt| lt.span).collect();
+                err.span_note(spans, "these named lifetimes are available to use");
+                if Some("") == snippet.as_deref() {
+                    // This happens when we have `Foo<T>` where we point at the space before `T`,
+                    // but this can be confusing so we give a suggestion with placeholders.
+                    err.span_suggestion_verbose(
+                        span,
+                        "consider using one of the available lifetimes here",
+                        "'lifetime, ".repeat(count),
+                        Applicability::HasPlaceholders,
+                    );
+                }
+            }
             _ => {}
         }
     }

src/test/ui/associated-types/bound-lifetime-in-binding-only.elision.stderr

@@ -5,7 +5,7 @@ LL | fn elision<T: Fn() -> &i32>() {
    |                       ^ expected named lifetime parameter
    |
    = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
-help: consider using the named lifetime
+help: consider using the `'static` lifetime
    |
 LL | fn elision<T: Fn() -> &'static i32>() {
    |                       ^^^^^^^^

src/test/ui/associated-types/bound-lifetime-in-return-only.elision.stderr

@@ -5,7 +5,7 @@ LL | fn elision(_: fn() -> &i32) {
    |                       ^ expected named lifetime parameter
    |
    = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
-help: consider using the named lifetime
+help: consider using the `'static` lifetime
    |
 LL | fn elision(_: fn() -> &'static i32) {
    |                       ^^^^^^^^

src/test/ui/async-await/issues/issue-63388-2.stderr

@@ -7,7 +7,7 @@ LL |     ) -> &dyn Foo
    |          ^ expected named lifetime parameter
    |
    = help: this function's return type contains a borrowed value, but the signature does not say whether it is borrowed from `foo` or `bar`
-help: consider using the named lifetime
+help: consider using the `'a` lifetime
    |
 LL |     ) -> &'a dyn Foo
    |          ^^^

src/test/ui/c-variadic/variadic-ffi-6.stderr

@@ -5,7 +5,7 @@ LL | ) -> &usize {
    |      ^ expected named lifetime parameter
    |
    = help: this function's return type contains a borrowed value with an elided lifetime, but the lifetime cannot be derived from the arguments
-help: consider using the named lifetime
+help: consider using the `'static` lifetime
    |
 LL | ) -> &'static usize {
    |      ^^^^^^^^

src/test/ui/foreign-fn-return-lifetime.stderr

@@ -5,7 +5,7 @@ LL |     pub fn f() -> &u8;
    |                   ^ expected named lifetime parameter
    |
    = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
-help: consider using the named lifetime
+help: consider using the `'static` lifetime
    |
 LL |     pub fn f() -> &'static u8;
    |                   ^^^^^^^^

src/test/ui/generics/issue-65285-incorrect-explicit-lifetime-name-needed.stderr

@@ -9,14 +9,26 @@ error[E0106]: missing lifetime specifier
    |
 LL |     fn foo<'b, L: X<&'b Nested<K>>>();
    |                     ^ expected named lifetime parameter
+   |
+note: these named lifetimes are available to use
+  --> $DIR/issue-65285-incorrect-explicit-lifetime-name-needed.rs:9:12
+   |
+LL | trait X<'a, K: 'a> {
+   |         ^^
+LL |     fn foo<'b, L: X<&'b Nested<K>>>();
+   |            ^^
+help: consider using one of the available lifetimes here
+   |
+LL |     fn foo<'b, L: X<'lifetime, &'b Nested<K>>>();
+   |                     ^^^^^^^^^^
 
 error[E0106]: missing lifetime specifier
   --> $DIR/issue-65285-incorrect-explicit-lifetime-name-needed.rs:13:17
    |
 LL | fn bar<'b, L: X<&'b Nested<i32>>>(){}
    |                 ^ expected named lifetime parameter
    |
-help: consider using the named lifetime
+help: consider using the `'b` lifetime
    |
 LL | fn bar<'b, L: X<'b, &'b Nested<i32>>>(){}
    |                 ^^^

src/test/ui/issues/issue-13497.stderr

@@ -5,7 +5,7 @@ LL |     &str
    |     ^ expected named lifetime parameter
    |
    = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
-help: consider using the named lifetime
+help: consider using the `'static` lifetime
    |
 LL |     &'static str
    |     ^^^^^^^^

src/test/ui/issues/issue-26638.stderr

@@ -17,7 +17,7 @@ LL | fn parse_type_2(iter: fn(&u8)->&u8) -> &str { iter() }
    |                                        ^ expected named lifetime parameter
    |
    = help: this function's return type contains a borrowed value with an elided lifetime, but the lifetime cannot be derived from the arguments
-help: consider using the named lifetime
+help: consider using the `'static` lifetime
    |
 LL | fn parse_type_2(iter: fn(&u8)->&u8) -> &'static str { iter() }
    |                                        ^^^^^^^^
@@ -29,7 +29,7 @@ LL | fn parse_type_3() -> &str { unimplemented!() }
    |                      ^ expected named lifetime parameter
    |
    = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
-help: consider using the named lifetime
+help: consider using the `'static` lifetime
    |
 LL | fn parse_type_3() -> &'static str { unimplemented!() }
    |                      ^^^^^^^^

src/test/ui/lifetimes/lifetime-elision-return-type-requires-explicit-lifetime.stderr

@@ -5,7 +5,7 @@ LL | fn f() -> &isize {
    |           ^ expected named lifetime parameter
    |
    = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
-help: consider using the named lifetime
+help: consider using the `'static` lifetime
    |
 LL | fn f() -> &'static isize {
    |           ^^^^^^^^
@@ -41,7 +41,7 @@ LL | fn i(_x: isize) -> &isize {
    |                    ^ expected named lifetime parameter
    |
    = help: this function's return type contains a borrowed value with an elided lifetime, but the lifetime cannot be derived from the arguments
-help: consider using the named lifetime
+help: consider using the `'static` lifetime
    |
 LL | fn i(_x: isize) -> &'static isize {
    |                    ^^^^^^^^
@@ -53,7 +53,7 @@ LL | fn j(_x: StaticStr) -> &isize {
    |                        ^ expected named lifetime parameter
    |
    = help: this function's return type contains a borrowed value with an elided lifetime, but the lifetime cannot be derived from the arguments
-help: consider using the named lifetime
+help: consider using the `'static` lifetime
    |
 LL | fn j(_x: StaticStr) -> &'static isize {
    |                        ^^^^^^^^
@@ -65,7 +65,7 @@ LL | fn k<'a, T: WithLifetime<'a>>(_x: T::Output) -> &isize {
    |                                                 ^ expected named lifetime parameter
    |
    = help: this function's return type contains a borrowed value with an elided lifetime, but the lifetime cannot be derived from the arguments
-help: consider using the named lifetime
+help: consider using the `'a` lifetime
    |
 LL | fn k<'a, T: WithLifetime<'a>>(_x: T::Output) -> &'a isize {
    |                                                 ^^^