Rollup merge of #133187 - ehuss:reference-diagnostic, r=jieyouxu

Add reference annotations for diagnostic attributes

This adds reference annotations for `diagnostic::on_unimplmented` and the `diagnostic` namespace in general.

There's also a rename for a test that looks like it was put in the wrong location.

28 files changed, 170 insertions, 147 deletions

diff --git a/tests/ui/diagnostic_namespace/deny_malformed_attribute.rs b/tests/ui/diagnostic_namespace/deny_malformed_attribute.rs
index 1d946a14aff..a46c856d38e 100644
--- a/tests/ui/diagnostic_namespace/deny_malformed_attribute.rs
+++ b/tests/ui/diagnostic_namespace/deny_malformed_attribute.rs
@@ -1,3 +1,5 @@
+//@ reference: attributes.diagnostic.namespace.unknown-invalid-syntax
+
 #![deny(unknown_or_malformed_diagnostic_attributes)]
 
 #[diagnostic::unknown_attribute]
diff --git a/tests/ui/diagnostic_namespace/deny_malformed_attribute.stderr b/tests/ui/diagnostic_namespace/deny_malformed_attribute.stderr
index a646d3613de..32be9db5317 100644
--- a/tests/ui/diagnostic_namespace/deny_malformed_attribute.stderr
+++ b/tests/ui/diagnostic_namespace/deny_malformed_attribute.stderr
@@ -1,11 +1,11 @@
 error: unknown diagnostic attribute
-  --> $DIR/deny_malformed_attribute.rs:3:15
+  --> $DIR/deny_malformed_attribute.rs:5:15
    |
 LL | #[diagnostic::unknown_attribute]
    |               ^^^^^^^^^^^^^^^^^
    |
 note: the lint level is defined here
-  --> $DIR/deny_malformed_attribute.rs:1:9
+  --> $DIR/deny_malformed_attribute.rs:3:9
    |
 LL | #![deny(unknown_or_malformed_diagnostic_attributes)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/tests/ui/diagnostic_namespace/malformed_foreign_on_unimplemented.rs b/tests/ui/diagnostic_namespace/malformed_foreign_on_unimplemented.rs
index 8b7467a17d0..b90dd0c7c94 100644
--- a/tests/ui/diagnostic_namespace/malformed_foreign_on_unimplemented.rs
+++ b/tests/ui/diagnostic_namespace/malformed_foreign_on_unimplemented.rs
@@ -1,5 +1,6 @@
 //@ edition:2021
 //@ aux-build:bad_on_unimplemented.rs
+//@ reference: attributes.diagnostic.on_unimplemented.syntax
 
 // Do not ICE when encountering a malformed `#[diagnostic::on_unimplemented]` annotation in a
 // dependency when incorrectly used (#124651).
diff --git a/tests/ui/diagnostic_namespace/malformed_foreign_on_unimplemented.stderr b/tests/ui/diagnostic_namespace/malformed_foreign_on_unimplemented.stderr
index c3e56550b70..f1258ad6b9a 100644
--- a/tests/ui/diagnostic_namespace/malformed_foreign_on_unimplemented.stderr
+++ b/tests/ui/diagnostic_namespace/malformed_foreign_on_unimplemented.stderr
@@ -1,5 +1,5 @@
 error[E0277]: the trait bound `(): bad_on_unimplemented::MissingAttr` is not satisfied
-  --> $DIR/malformed_foreign_on_unimplemented.rs:22:18
+  --> $DIR/malformed_foreign_on_unimplemented.rs:23:18
    |
 LL |     missing_attr(());
    |     ------------ ^^ the trait `bad_on_unimplemented::MissingAttr` is not implemented for `()`
@@ -7,13 +7,13 @@ LL |     missing_attr(());
    |     required by a bound introduced by this call
    |
 note: required by a bound in `missing_attr`
-  --> $DIR/malformed_foreign_on_unimplemented.rs:11:20
+  --> $DIR/malformed_foreign_on_unimplemented.rs:12:20
    |
 LL | fn missing_attr<T: MissingAttr>(_: T) {}
    |                    ^^^^^^^^^^^ required by this bound in `missing_attr`
 
 error[E0277]: the trait bound `(): bad_on_unimplemented::DuplicateAttr` is not satisfied
-  --> $DIR/malformed_foreign_on_unimplemented.rs:23:20
+  --> $DIR/malformed_foreign_on_unimplemented.rs:24:20
    |
 LL |     duplicate_attr(());
    |     -------------- ^^ a
@@ -22,13 +22,13 @@ LL |     duplicate_attr(());
    |
    = help: the trait `bad_on_unimplemented::DuplicateAttr` is not implemented for `()`
 note: required by a bound in `duplicate_attr`
-  --> $DIR/malformed_foreign_on_unimplemented.rs:12:22
+  --> $DIR/malformed_foreign_on_unimplemented.rs:13:22
    |
 LL | fn duplicate_attr<T: DuplicateAttr>(_: T) {}
    |                      ^^^^^^^^^^^^^ required by this bound in `duplicate_attr`
 
 error[E0277]: the trait bound `(): bad_on_unimplemented::NotMetaList` is not satisfied
-  --> $DIR/malformed_foreign_on_unimplemented.rs:24:19
+  --> $DIR/malformed_foreign_on_unimplemented.rs:25:19
    |
 LL |     not_meta_list(());
    |     ------------- ^^ the trait `bad_on_unimplemented::NotMetaList` is not implemented for `()`
@@ -36,13 +36,13 @@ LL |     not_meta_list(());
    |     required by a bound introduced by this call
    |
 note: required by a bound in `not_meta_list`
-  --> $DIR/malformed_foreign_on_unimplemented.rs:13:21
+  --> $DIR/malformed_foreign_on_unimplemented.rs:14:21
    |
 LL | fn not_meta_list<T: NotMetaList>(_: T) {}
    |                     ^^^^^^^^^^^ required by this bound in `not_meta_list`
 
 error[E0277]: the trait bound `(): bad_on_unimplemented::Empty` is not satisfied
-  --> $DIR/malformed_foreign_on_unimplemented.rs:25:11
+  --> $DIR/malformed_foreign_on_unimplemented.rs:26:11
    |
 LL |     empty(());
    |     ----- ^^ the trait `bad_on_unimplemented::Empty` is not implemented for `()`
@@ -50,13 +50,13 @@ LL |     empty(());
    |     required by a bound introduced by this call
    |
 note: required by a bound in `empty`
-  --> $DIR/malformed_foreign_on_unimplemented.rs:14:13
+  --> $DIR/malformed_foreign_on_unimplemented.rs:15:13
    |
 LL | fn empty<T: Empty>(_: T) {}
    |             ^^^^^ required by this bound in `empty`
 
 error[E0277]: the trait bound `(): bad_on_unimplemented::WrongDelim` is not satisfied
-  --> $DIR/malformed_foreign_on_unimplemented.rs:26:17
+  --> $DIR/malformed_foreign_on_unimplemented.rs:27:17
    |
 LL |     wrong_delim(());
    |     ----------- ^^ the trait `bad_on_unimplemented::WrongDelim` is not implemented for `()`
@@ -64,13 +64,13 @@ LL |     wrong_delim(());
    |     required by a bound introduced by this call
    |
 note: required by a bound in `wrong_delim`
-  --> $DIR/malformed_foreign_on_unimplemented.rs:15:19
+  --> $DIR/malformed_foreign_on_unimplemented.rs:16:19
    |
 LL | fn wrong_delim<T: WrongDelim>(_: T) {}
    |                   ^^^^^^^^^^ required by this bound in `wrong_delim`
 
 error[E0277]: the trait bound `(): bad_on_unimplemented::BadFormatter<()>` is not satisfied
-  --> $DIR/malformed_foreign_on_unimplemented.rs:27:19
+  --> $DIR/malformed_foreign_on_unimplemented.rs:28:19
    |
 LL |     bad_formatter(());
    |     ------------- ^^ ()
@@ -79,13 +79,13 @@ LL |     bad_formatter(());
    |
    = help: the trait `bad_on_unimplemented::BadFormatter<()>` is not implemented for `()`
 note: required by a bound in `bad_formatter`
-  --> $DIR/malformed_foreign_on_unimplemented.rs:16:21
+  --> $DIR/malformed_foreign_on_unimplemented.rs:17:21
    |
 LL | fn bad_formatter<T: BadFormatter<()>>(_: T) {}
    |                     ^^^^^^^^^^^^^^^^ required by this bound in `bad_formatter`
 
 error[E0277]: the trait bound `(): bad_on_unimplemented::NoImplicitArgs` is not satisfied
-  --> $DIR/malformed_foreign_on_unimplemented.rs:28:22
+  --> $DIR/malformed_foreign_on_unimplemented.rs:29:22
    |
 LL |     no_implicit_args(());
    |     ---------------- ^^ test {}
@@ -94,13 +94,13 @@ LL |     no_implicit_args(());
    |
    = help: the trait `bad_on_unimplemented::NoImplicitArgs` is not implemented for `()`
 note: required by a bound in `no_implicit_args`
-  --> $DIR/malformed_foreign_on_unimplemented.rs:17:24
+  --> $DIR/malformed_foreign_on_unimplemented.rs:18:24
    |
 LL | fn no_implicit_args<T: NoImplicitArgs>(_: T) {}
    |                        ^^^^^^^^^^^^^^ required by this bound in `no_implicit_args`
 
 error[E0277]: the trait bound `(): bad_on_unimplemented::MissingArg` is not satisfied
-  --> $DIR/malformed_foreign_on_unimplemented.rs:29:17
+  --> $DIR/malformed_foreign_on_unimplemented.rs:30:17
    |
 LL |     missing_arg(());
    |     ----------- ^^ {missing}
@@ -109,13 +109,13 @@ LL |     missing_arg(());
    |
    = help: the trait `bad_on_unimplemented::MissingArg` is not implemented for `()`
 note: required by a bound in `missing_arg`
-  --> $DIR/malformed_foreign_on_unimplemented.rs:18:19
+  --> $DIR/malformed_foreign_on_unimplemented.rs:19:19
    |
 LL | fn missing_arg<T: MissingArg>(_: T) {}
    |                   ^^^^^^^^^^ required by this bound in `missing_arg`
 
 error[E0277]: the trait bound `(): bad_on_unimplemented::BadArg` is not satisfied
-  --> $DIR/malformed_foreign_on_unimplemented.rs:30:13
+  --> $DIR/malformed_foreign_on_unimplemented.rs:31:13
    |
 LL |     bad_arg(());
    |     ------- ^^ {_}
@@ -124,7 +124,7 @@ LL |     bad_arg(());
    |
    = help: the trait `bad_on_unimplemented::BadArg` is not implemented for `()`
 note: required by a bound in `bad_arg`
-  --> $DIR/malformed_foreign_on_unimplemented.rs:19:15
+  --> $DIR/malformed_foreign_on_unimplemented.rs:20:15
    |
 LL | fn bad_arg<T: BadArg>(_: T) {}
    |               ^^^^^^ required by this bound in `bad_arg`
diff --git a/tests/ui/diagnostic_namespace/non_existing_attributes_accepted.rs b/tests/ui/diagnostic_namespace/non_existing_attributes_accepted.rs
index f6957b1448d..02c1352482c 100644
--- a/tests/ui/diagnostic_namespace/non_existing_attributes_accepted.rs
+++ b/tests/ui/diagnostic_namespace/non_existing_attributes_accepted.rs
@@ -1,4 +1,5 @@
 //@ check-pass
+//@ reference: attributes.diagnostic.namespace.unknown-invalid-syntax
 #[diagnostic::non_existing_attribute]
 //~^WARN unknown diagnostic attribute
 pub trait Bar {
diff --git a/tests/ui/diagnostic_namespace/non_existing_attributes_accepted.stderr b/tests/ui/diagnostic_namespace/non_existing_attributes_accepted.stderr
index c073ec9b103..753077b365e 100644
--- a/tests/ui/diagnostic_namespace/non_existing_attributes_accepted.stderr
+++ b/tests/ui/diagnostic_namespace/non_existing_attributes_accepted.stderr
@@ -1,5 +1,5 @@
 warning: unknown diagnostic attribute
-  --> $DIR/non_existing_attributes_accepted.rs:2:15
+  --> $DIR/non_existing_attributes_accepted.rs:3:15
    |
 LL | #[diagnostic::non_existing_attribute]
    |               ^^^^^^^^^^^^^^^^^^^^^^
@@ -7,7 +7,7 @@ LL | #[diagnostic::non_existing_attribute]
    = note: `#[warn(unknown_or_malformed_diagnostic_attributes)]` on by default
 
 warning: unknown diagnostic attribute
-  --> $DIR/non_existing_attributes_accepted.rs:7:15
+  --> $DIR/non_existing_attributes_accepted.rs:8:15
    |
 LL | #[diagnostic::non_existing_attribute(with_option = "foo")]
    |               ^^^^^^^^^^^^^^^^^^^^^^
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/broken_format.rs b/tests/ui/diagnostic_namespace/on_unimplemented/broken_format.rs
index 3ca58b28181..44f269eb967 100644
--- a/tests/ui/diagnostic_namespace/on_unimplemented/broken_format.rs
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/broken_format.rs
@@ -1,3 +1,4 @@
+//@ reference: attributes.diagnostic.on_unimplemented.invalid-string
 #[diagnostic::on_unimplemented(message = "{{Test } thing")]
 //~^WARN unmatched `}` found
 //~|WARN unmatched `}` found
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/broken_format.stderr b/tests/ui/diagnostic_namespace/on_unimplemented/broken_format.stderr
index b4ed06cb63d..7fd51c7527f 100644
--- a/tests/ui/diagnostic_namespace/on_unimplemented/broken_format.stderr
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/broken_format.stderr
@@ -1,5 +1,5 @@
 warning: unmatched `}` found
-  --> $DIR/broken_format.rs:1:32
+  --> $DIR/broken_format.rs:2:32
    |
 LL | #[diagnostic::on_unimplemented(message = "{{Test } thing")]
    |                                ^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -7,7 +7,7 @@ LL | #[diagnostic::on_unimplemented(message = "{{Test } thing")]
    = note: `#[warn(unknown_or_malformed_diagnostic_attributes)]` on by default
 
 warning: positional format arguments are not allowed here
-  --> $DIR/broken_format.rs:6:32
+  --> $DIR/broken_format.rs:7:32
    |
 LL | #[diagnostic::on_unimplemented(message = "Test {}")]
    |                                ^^^^^^^^^^^^^^^^^^^
@@ -15,7 +15,7 @@ LL | #[diagnostic::on_unimplemented(message = "Test {}")]
    = help: only named format arguments with the name of one of the generic types are allowed in this context
 
 warning: positional format arguments are not allowed here
-  --> $DIR/broken_format.rs:11:32
+  --> $DIR/broken_format.rs:12:32
    |
 LL | #[diagnostic::on_unimplemented(message = "Test {1:}")]
    |                                ^^^^^^^^^^^^^^^^^^^^^
@@ -23,7 +23,7 @@ LL | #[diagnostic::on_unimplemented(message = "Test {1:}")]
    = help: only named format arguments with the name of one of the generic types are allowed in this context
 
 warning: invalid format specifier
-  --> $DIR/broken_format.rs:16:32
+  --> $DIR/broken_format.rs:17:32
    |
 LL | #[diagnostic::on_unimplemented(message = "Test {Self:123}")]
    |                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -31,19 +31,19 @@ LL | #[diagnostic::on_unimplemented(message = "Test {Self:123}")]
    = help: no format specifier are supported in this position
 
 warning: expected `}`, found `!`
-  --> $DIR/broken_format.rs:21:32
+  --> $DIR/broken_format.rs:22:32
    |
 LL | #[diagnostic::on_unimplemented(message = "Test {Self:!}")]
    |                                ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unmatched `}` found
-  --> $DIR/broken_format.rs:21:32
+  --> $DIR/broken_format.rs:22:32
    |
 LL | #[diagnostic::on_unimplemented(message = "Test {Self:!}")]
    |                                ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unmatched `}` found
-  --> $DIR/broken_format.rs:1:32
+  --> $DIR/broken_format.rs:2:32
    |
 LL | #[diagnostic::on_unimplemented(message = "{{Test } thing")]
    |                                ^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -51,7 +51,7 @@ LL | #[diagnostic::on_unimplemented(message = "{{Test } thing")]
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error[E0277]: {{Test } thing
-  --> $DIR/broken_format.rs:35:13
+  --> $DIR/broken_format.rs:36:13
    |
 LL |     check_1(());
    |     ------- ^^ the trait `ImportantTrait1` is not implemented for `()`
@@ -59,18 +59,18 @@ LL |     check_1(());
    |     required by a bound introduced by this call
    |
 help: this trait has no implementations, consider adding one
-  --> $DIR/broken_format.rs:4:1
+  --> $DIR/broken_format.rs:5:1
    |
 LL | trait ImportantTrait1 {}
    | ^^^^^^^^^^^^^^^^^^^^^
 note: required by a bound in `check_1`
-  --> $DIR/broken_format.rs:28:20
+  --> $DIR/broken_format.rs:29:20
    |
 LL | fn check_1(_: impl ImportantTrait1) {}
    |                    ^^^^^^^^^^^^^^^ required by this bound in `check_1`
 
 warning: positional format arguments are not allowed here
-  --> $DIR/broken_format.rs:6:32
+  --> $DIR/broken_format.rs:7:32
    |
 LL | #[diagnostic::on_unimplemented(message = "Test {}")]
    |                                ^^^^^^^^^^^^^^^^^^^
@@ -79,7 +79,7 @@ LL | #[diagnostic::on_unimplemented(message = "Test {}")]
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error[E0277]: Test {}
-  --> $DIR/broken_format.rs:37:13
+  --> $DIR/broken_format.rs:38:13
    |
 LL |     check_2(());
    |     ------- ^^ the trait `ImportantTrait2` is not implemented for `()`
@@ -87,18 +87,18 @@ LL |     check_2(());
    |     required by a bound introduced by this call
    |
 help: this trait has no implementations, consider adding one
-  --> $DIR/broken_format.rs:9:1
+  --> $DIR/broken_format.rs:10:1
    |
 LL | trait ImportantTrait2 {}
    | ^^^^^^^^^^^^^^^^^^^^^
 note: required by a bound in `check_2`
-  --> $DIR/broken_format.rs:29:20
+  --> $DIR/broken_format.rs:30:20
    |
 LL | fn check_2(_: impl ImportantTrait2) {}
    |                    ^^^^^^^^^^^^^^^ required by this bound in `check_2`
 
 warning: positional format arguments are not allowed here
-  --> $DIR/broken_format.rs:11:32
+  --> $DIR/broken_format.rs:12:32
    |
 LL | #[diagnostic::on_unimplemented(message = "Test {1:}")]
    |                                ^^^^^^^^^^^^^^^^^^^^^
@@ -107,7 +107,7 @@ LL | #[diagnostic::on_unimplemented(message = "Test {1:}")]
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error[E0277]: Test {1}
-  --> $DIR/broken_format.rs:39:13
+  --> $DIR/broken_format.rs:40:13
    |
 LL |     check_3(());
    |     ------- ^^ the trait `ImportantTrait3` is not implemented for `()`
@@ -115,18 +115,18 @@ LL |     check_3(());
    |     required by a bound introduced by this call
    |
 help: this trait has no implementations, consider adding one
-  --> $DIR/broken_format.rs:14:1
+  --> $DIR/broken_format.rs:15:1
    |
 LL | trait ImportantTrait3 {}
    | ^^^^^^^^^^^^^^^^^^^^^
 note: required by a bound in `check_3`
-  --> $DIR/broken_format.rs:30:20
+  --> $DIR/broken_format.rs:31:20
    |
 LL | fn check_3(_: impl ImportantTrait3) {}
    |                    ^^^^^^^^^^^^^^^ required by this bound in `check_3`
 
 warning: invalid format specifier
-  --> $DIR/broken_format.rs:16:32
+  --> $DIR/broken_format.rs:17:32
    |
 LL | #[diagnostic::on_unimplemented(message = "Test {Self:123}")]
    |                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -135,7 +135,7 @@ LL | #[diagnostic::on_unimplemented(message = "Test {Self:123}")]
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error[E0277]: Test ()
-  --> $DIR/broken_format.rs:41:13
+  --> $DIR/broken_format.rs:42:13
    |
 LL |     check_4(());
    |     ------- ^^ the trait `ImportantTrait4` is not implemented for `()`
@@ -143,18 +143,18 @@ LL |     check_4(());
    |     required by a bound introduced by this call
    |
 help: this trait has no implementations, consider adding one
-  --> $DIR/broken_format.rs:19:1
+  --> $DIR/broken_format.rs:20:1
    |
 LL | trait ImportantTrait4 {}
    | ^^^^^^^^^^^^^^^^^^^^^
 note: required by a bound in `check_4`
-  --> $DIR/broken_format.rs:31:20
+  --> $DIR/broken_format.rs:32:20
    |
 LL | fn check_4(_: impl ImportantTrait4) {}
    |                    ^^^^^^^^^^^^^^^ required by this bound in `check_4`
 
 warning: expected `}`, found `!`
-  --> $DIR/broken_format.rs:21:32
+  --> $DIR/broken_format.rs:22:32
    |
 LL | #[diagnostic::on_unimplemented(message = "Test {Self:!}")]
    |                                ^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -162,7 +162,7 @@ LL | #[diagnostic::on_unimplemented(message = "Test {Self:!}")]
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 warning: unmatched `}` found
-  --> $DIR/broken_format.rs:21:32
+  --> $DIR/broken_format.rs:22:32
    |
 LL | #[diagnostic::on_unimplemented(message = "Test {Self:!}")]
    |                                ^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -170,7 +170,7 @@ LL | #[diagnostic::on_unimplemented(message = "Test {Self:!}")]
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error[E0277]: Test {Self:!}
-  --> $DIR/broken_format.rs:43:13
+  --> $DIR/broken_format.rs:44:13
    |
 LL |     check_5(());
    |     ------- ^^ the trait `ImportantTrait5` is not implemented for `()`
@@ -178,12 +178,12 @@ LL |     check_5(());
    |     required by a bound introduced by this call
    |
 help: this trait has no implementations, consider adding one
-  --> $DIR/broken_format.rs:26:1
+  --> $DIR/broken_format.rs:27:1
    |
 LL | trait ImportantTrait5 {}
    | ^^^^^^^^^^^^^^^^^^^^^
 note: required by a bound in `check_5`
-  --> $DIR/broken_format.rs:32:20
+  --> $DIR/broken_format.rs:33:20
    |
 LL | fn check_5(_: impl ImportantTrait5) {}
    |                    ^^^^^^^^^^^^^^^ required by this bound in `check_5`
diff --git a/tests/ui/traits/custom-on-unimplemented-diagnostic.rs b/tests/ui/diagnostic_namespace/on_unimplemented/custom-on-unimplemented-diagnostic.rs
index d7e257ef3bb..1173c939038 100644
--- a/tests/ui/traits/custom-on-unimplemented-diagnostic.rs
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/custom-on-unimplemented-diagnostic.rs
@@ -1,3 +1,5 @@
+//@ reference: attributes.diagnostic.on_unimplemented.intro
+//@ reference: attributes.diagnostic.on_unimplemented.keys
 #[diagnostic::on_unimplemented(message = "my message", label = "my label", note = "my note")]
 pub trait ProviderLt {}
 
diff --git a/tests/ui/traits/custom-on-unimplemented-diagnostic.stderr b/tests/ui/diagnostic_namespace/on_unimplemented/custom-on-unimplemented-diagnostic.stderr
index f9788360d06..4c1838620b3 100644
--- a/tests/ui/traits/custom-on-unimplemented-diagnostic.stderr
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/custom-on-unimplemented-diagnostic.stderr
@@ -1,5 +1,5 @@
 error[E0599]: my message
-  --> $DIR/custom-on-unimplemented-diagnostic.rs:15:7
+  --> $DIR/custom-on-unimplemented-diagnostic.rs:17:7
    |
 LL | struct B;
    | -------- method `request` not found for this struct because it doesn't satisfy `B: ProviderExt` or `B: ProviderLt`
@@ -8,7 +8,7 @@ LL |     B.request();
    |       ^^^^^^^ my label
    |
 note: trait bound `B: ProviderLt` was not satisfied
-  --> $DIR/custom-on-unimplemented-diagnostic.rs:10:18
+  --> $DIR/custom-on-unimplemented-diagnostic.rs:12:18
    |
 LL | impl<T: ?Sized + ProviderLt> ProviderExt for T {}
    |                  ^^^^^^^^^^  -----------     -
@@ -16,13 +16,13 @@ LL | impl<T: ?Sized + ProviderLt> ProviderExt for T {}
    |                  unsatisfied trait bound introduced here
    = note: my note
 note: the trait `ProviderLt` must be implemented
-  --> $DIR/custom-on-unimplemented-diagnostic.rs:2:1
+  --> $DIR/custom-on-unimplemented-diagnostic.rs:4:1
    |
 LL | pub trait ProviderLt {}
    | ^^^^^^^^^^^^^^^^^^^^
    = help: items from traits can only be used if the trait is implemented and in scope
 note: `ProviderExt` defines an item `request`, perhaps you need to implement it
-  --> $DIR/custom-on-unimplemented-diagnostic.rs:4:1
+  --> $DIR/custom-on-unimplemented-diagnostic.rs:6:1
    |
 LL | pub trait ProviderExt {
    | ^^^^^^^^^^^^^^^^^^^^^
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/do_not_accept_options_of_the_internal_rustc_attribute.rs b/tests/ui/diagnostic_namespace/on_unimplemented/do_not_accept_options_of_the_internal_rustc_attribute.rs
index 30a85ff2199..b76b550fcb2 100644
--- a/tests/ui/diagnostic_namespace/on_unimplemented/do_not_accept_options_of_the_internal_rustc_attribute.rs
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/do_not_accept_options_of_the_internal_rustc_attribute.rs
@@ -1,3 +1,7 @@
+//@ reference: attributes.diagnostic.on_unimplemented.format-parameters
+//@ reference: attributes.diagnostic.on_unimplemented.keys
+//@ reference: attributes.diagnostic.on_unimplemented.syntax
+//@ reference: attributes.diagnostic.on_unimplemented.invalid-formats
 #[diagnostic::on_unimplemented(
     on(_Self = "&str"),
     //~^WARN malformed `on_unimplemented` attribute
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/do_not_accept_options_of_the_internal_rustc_attribute.stderr b/tests/ui/diagnostic_namespace/on_unimplemented/do_not_accept_options_of_the_internal_rustc_attribute.stderr
index e34b917f67e..bb455d92940 100644
--- a/tests/ui/diagnostic_namespace/on_unimplemented/do_not_accept_options_of_the_internal_rustc_attribute.stderr
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/do_not_accept_options_of_the_internal_rustc_attribute.stderr
@@ -1,5 +1,5 @@
 warning: `#[diagnostic::on_unimplemented]` can only be applied to trait definitions
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:22:1
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:26:1
    |
 LL | #[diagnostic::on_unimplemented(message = "Not allowed to apply it on a impl")]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -7,7 +7,7 @@ LL | #[diagnostic::on_unimplemented(message = "Not allowed to apply it on a impl
    = note: `#[warn(unknown_or_malformed_diagnostic_attributes)]` on by default
 
 warning: malformed `on_unimplemented` attribute
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:2:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:6:5
    |
 LL |     on(_Self = "&str"),
    |     ^^^^^^^^^^^^^^^^^^ invalid option found here
@@ -15,7 +15,7 @@ LL |     on(_Self = "&str"),
    = help: only `message`, `note` and `label` are allowed as options
 
 warning: malformed `on_unimplemented` attribute
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:8:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:12:5
    |
 LL |     parent_label = "in this scope",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ invalid option found here
@@ -23,7 +23,7 @@ LL |     parent_label = "in this scope",
    = help: only `message`, `note` and `label` are allowed as options
 
 warning: malformed `on_unimplemented` attribute
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:11:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:15:5
    |
 LL |     append_const_msg
    |     ^^^^^^^^^^^^^^^^ invalid option found here
@@ -31,7 +31,7 @@ LL |     append_const_msg
    = help: only `message`, `note` and `label` are allowed as options
 
 warning: malformed `on_unimplemented` attribute
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:17:32
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:21:32
    |
 LL | #[diagnostic::on_unimplemented = "Message"]
    |                                ^^^^^^^^^^^ invalid option found here
@@ -39,7 +39,7 @@ LL | #[diagnostic::on_unimplemented = "Message"]
    = help: only `message`, `note` and `label` are allowed as options
 
 warning: there is no parameter `from_desugaring` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:29:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:33:5
    |
 LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -47,7 +47,7 @@ LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    = help: expect either a generic argument name or `{Self}` as format argument
 
 warning: there is no parameter `direct` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:29:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:33:5
    |
 LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -55,7 +55,7 @@ LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    = help: expect either a generic argument name or `{Self}` as format argument
 
 warning: there is no parameter `cause` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:29:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:33:5
    |
 LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -63,7 +63,7 @@ LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    = help: expect either a generic argument name or `{Self}` as format argument
 
 warning: there is no parameter `integral` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:29:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:33:5
    |
 LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -71,7 +71,7 @@ LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    = help: expect either a generic argument name or `{Self}` as format argument
 
 warning: there is no parameter `integer` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:29:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:33:5
    |
 LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -79,7 +79,7 @@ LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    = help: expect either a generic argument name or `{Self}` as format argument
 
 warning: there is no parameter `float` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:40:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:44:5
    |
 LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -87,7 +87,7 @@ LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    = help: expect either a generic argument name or `{Self}` as format argument
 
 warning: there is no parameter `_Self` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:40:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:44:5
    |
 LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -95,7 +95,7 @@ LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    = help: expect either a generic argument name or `{Self}` as format argument
 
 warning: there is no parameter `crate_local` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:40:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:44:5
    |
 LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -103,7 +103,7 @@ LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    = help: expect either a generic argument name or `{Self}` as format argument
 
 warning: there is no parameter `Trait` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:40:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:44:5
    |
 LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -111,7 +111,7 @@ LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    = help: expect either a generic argument name or `{Self}` as format argument
 
 warning: there is no parameter `ItemContext` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:40:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:44:5
    |
 LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -119,7 +119,7 @@ LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    = help: expect either a generic argument name or `{Self}` as format argument
 
 warning: malformed `on_unimplemented` attribute
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:2:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:6:5
    |
 LL |     on(_Self = "&str"),
    |     ^^^^^^^^^^^^^^^^^^ invalid option found here
@@ -128,7 +128,7 @@ LL |     on(_Self = "&str"),
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 warning: malformed `on_unimplemented` attribute
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:8:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:12:5
    |
 LL |     parent_label = "in this scope",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ invalid option found here
@@ -137,7 +137,7 @@ LL |     parent_label = "in this scope",
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 warning: malformed `on_unimplemented` attribute
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:11:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:15:5
    |
 LL |     append_const_msg
    |     ^^^^^^^^^^^^^^^^ invalid option found here
@@ -146,7 +146,7 @@ LL |     append_const_msg
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error[E0277]: trait has `()` and `i32` as params
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:59:15
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:63:15
    |
 LL |     takes_foo(());
    |     --------- ^^ trait has `()` and `i32` as params
@@ -156,18 +156,18 @@ LL |     takes_foo(());
    = help: the trait `Foo<i32>` is not implemented for `()`
    = note: trait has `()` and `i32` as params
 help: this trait has no implementations, consider adding one
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:15:1
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:19:1
    |
 LL | trait Foo<T> {}
    | ^^^^^^^^^^^^
 note: required by a bound in `takes_foo`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:54:22
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:58:22
    |
 LL | fn takes_foo(_: impl Foo<i32>) {}
    |                      ^^^^^^^^ required by this bound in `takes_foo`
 
 warning: malformed `on_unimplemented` attribute
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:17:32
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:21:32
    |
 LL | #[diagnostic::on_unimplemented = "Message"]
    |                                ^^^^^^^^^^^ invalid option found here
@@ -176,7 +176,7 @@ LL | #[diagnostic::on_unimplemented = "Message"]
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error[E0277]: the trait bound `(): Bar` is not satisfied
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:61:15
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:65:15
    |
 LL |     takes_bar(());
    |     --------- ^^ the trait `Bar` is not implemented for `()`
@@ -185,13 +185,13 @@ LL |     takes_bar(());
    |
    = help: the trait `Bar` is implemented for `i32`
 note: required by a bound in `takes_bar`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:55:22
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:59:22
    |
 LL | fn takes_bar(_: impl Bar) {}
    |                      ^^^ required by this bound in `takes_bar`
 
 warning: there is no parameter `from_desugaring` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:29:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:33:5
    |
 LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -200,7 +200,7 @@ LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 warning: there is no parameter `direct` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:29:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:33:5
    |
 LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -209,7 +209,7 @@ LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 warning: there is no parameter `cause` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:29:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:33:5
    |
 LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -218,7 +218,7 @@ LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 warning: there is no parameter `integral` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:29:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:33:5
    |
 LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -227,7 +227,7 @@ LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 warning: there is no parameter `integer` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:29:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:33:5
    |
 LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -236,7 +236,7 @@ LL |     message = "{from_desugaring}{direct}{cause}{integral}{integer}",
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 warning: there is no parameter `float` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:40:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:44:5
    |
 LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -245,7 +245,7 @@ LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 warning: there is no parameter `_Self` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:40:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:44:5
    |
 LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -254,7 +254,7 @@ LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 warning: there is no parameter `crate_local` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:40:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:44:5
    |
 LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -263,7 +263,7 @@ LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 warning: there is no parameter `Trait` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:40:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:44:5
    |
 LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -272,7 +272,7 @@ LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 warning: there is no parameter `ItemContext` on trait `Baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:40:5
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:44:5
    |
 LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -281,7 +281,7 @@ LL |     label = "{float}{_Self}{crate_local}{Trait}{ItemContext}"
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error[E0277]: {from_desugaring}{direct}{cause}{integral}{integer}
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:63:15
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:67:15
    |
 LL |     takes_baz(());
    |     --------- ^^ {float}{_Self}{crate_local}{Trait}{ItemContext}
@@ -290,12 +290,12 @@ LL |     takes_baz(());
    |
    = help: the trait `Baz` is not implemented for `()`
 help: this trait has no implementations, consider adding one
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:52:1
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:56:1
    |
 LL | trait Baz {}
    | ^^^^^^^^^
 note: required by a bound in `takes_baz`
-  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:56:22
+  --> $DIR/do_not_accept_options_of_the_internal_rustc_attribute.rs:60:22
    |
 LL | fn takes_baz(_: impl Baz) {}
    |                      ^^^ required by this bound in `takes_baz`
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/do_not_fail_parsing_on_invalid_options_1.rs b/tests/ui/diagnostic_namespace/on_unimplemented/do_not_fail_parsing_on_invalid_options_1.rs
index b4234066bb1..8328c10d2a0 100644
--- a/tests/ui/diagnostic_namespace/on_unimplemented/do_not_fail_parsing_on_invalid_options_1.rs
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/do_not_fail_parsing_on_invalid_options_1.rs
@@ -1,3 +1,5 @@
+//@ reference: attributes.diagnostic.on_unimplemented.syntax
+//@ reference: attributes.diagnostic.on_unimplemented.unknown-keys
 #[diagnostic::on_unimplemented(unsupported = "foo")]
 //~^WARN malformed `on_unimplemented` attribute
 //~|WARN malformed `on_unimplemented` attribute
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/do_not_fail_parsing_on_invalid_options_1.stderr b/tests/ui/diagnostic_namespace/on_unimplemented/do_not_fail_parsing_on_invalid_options_1.stderr
index dc0c1948236..11263580b15 100644
--- a/tests/ui/diagnostic_namespace/on_unimplemented/do_not_fail_parsing_on_invalid_options_1.stderr
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/do_not_fail_parsing_on_invalid_options_1.stderr
@@ -1,5 +1,5 @@
 warning: `#[diagnostic::on_unimplemented]` can only be applied to trait definitions
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:6:1
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:8:1
    |
 LL | #[diagnostic::on_unimplemented(message = "Baz")]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -7,7 +7,7 @@ LL | #[diagnostic::on_unimplemented(message = "Baz")]
    = note: `#[warn(unknown_or_malformed_diagnostic_attributes)]` on by default
 
 warning: malformed `on_unimplemented` attribute
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:1:32
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:3:32
    |
 LL | #[diagnostic::on_unimplemented(unsupported = "foo")]
    |                                ^^^^^^^^^^^^^^^^^^^ invalid option found here
@@ -15,7 +15,7 @@ LL | #[diagnostic::on_unimplemented(unsupported = "foo")]
    = help: only `message`, `note` and `label` are allowed as options
 
 warning: malformed `on_unimplemented` attribute
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:10:50
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:12:50
    |
 LL | #[diagnostic::on_unimplemented(message = "Boom", unsupported = "Bar")]
    |                                                  ^^^^^^^^^^^^^^^^^^^ invalid option found here
@@ -23,7 +23,7 @@ LL | #[diagnostic::on_unimplemented(message = "Boom", unsupported = "Bar")]
    = help: only `message`, `note` and `label` are allowed as options
 
 warning: malformed `on_unimplemented` attribute
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:15:50
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:17:50
    |
 LL | #[diagnostic::on_unimplemented(message = "Boom", on(_Self = "i32", message = "whatever"))]
    |                                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ invalid option found here
@@ -31,7 +31,7 @@ LL | #[diagnostic::on_unimplemented(message = "Boom", on(_Self = "i32", message
    = help: only `message`, `note` and `label` are allowed as options
 
 warning: malformed `on_unimplemented` attribute
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:20:32
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:22:32
    |
 LL | #[diagnostic::on_unimplemented = "boom"]
    |                                ^^^^^^^^ invalid option found here
@@ -39,7 +39,7 @@ LL | #[diagnostic::on_unimplemented = "boom"]
    = help: only `message`, `note` and `label` are allowed as options
 
 warning: missing options for `on_unimplemented` attribute
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:24:1
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:26:1
    |
 LL | #[diagnostic::on_unimplemented]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -47,7 +47,7 @@ LL | #[diagnostic::on_unimplemented]
    = help: at least one of the `message`, `note` and `label` options are expected
 
 warning: there is no parameter `DoesNotExist` on trait `Test`
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:29:32
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:31:32
    |
 LL | #[diagnostic::on_unimplemented(message = "{DoesNotExist}")]
    |                                ^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -55,7 +55,7 @@ LL | #[diagnostic::on_unimplemented(message = "{DoesNotExist}")]
    = help: expect either a generic argument name or `{Self}` as format argument
 
 warning: malformed `on_unimplemented` attribute
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:1:32
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:3:32
    |
 LL | #[diagnostic::on_unimplemented(unsupported = "foo")]
    |                                ^^^^^^^^^^^^^^^^^^^ invalid option found here
@@ -64,7 +64,7 @@ LL | #[diagnostic::on_unimplemented(unsupported = "foo")]
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error[E0277]: the trait bound `i32: Foo` is not satisfied
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:41:14
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:43:14
    |
 LL |     take_foo(1_i32);
    |     -------- ^^^^^ the trait `Foo` is not implemented for `i32`
@@ -72,18 +72,18 @@ LL |     take_foo(1_i32);
    |     required by a bound introduced by this call
    |
 help: this trait has no implementations, consider adding one
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:4:1
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:6:1
    |
 LL | trait Foo {}
    | ^^^^^^^^^
 note: required by a bound in `take_foo`
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:34:21
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:36:21
    |
 LL | fn take_foo(_: impl Foo) {}
    |                     ^^^ required by this bound in `take_foo`
 
 warning: malformed `on_unimplemented` attribute
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:10:50
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:12:50
    |
 LL | #[diagnostic::on_unimplemented(message = "Boom", unsupported = "Bar")]
    |                                                  ^^^^^^^^^^^^^^^^^^^ invalid option found here
@@ -92,7 +92,7 @@ LL | #[diagnostic::on_unimplemented(message = "Boom", unsupported = "Bar")]
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error[E0277]: Boom
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:43:14
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:45:14
    |
 LL |     take_baz(1_i32);
    |     -------- ^^^^^ the trait `Baz` is not implemented for `i32`
@@ -100,18 +100,18 @@ LL |     take_baz(1_i32);
    |     required by a bound introduced by this call
    |
 help: this trait has no implementations, consider adding one
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:13:1
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:15:1
    |
 LL | trait Baz {}
    | ^^^^^^^^^
 note: required by a bound in `take_baz`
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:35:21
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:37:21
    |
 LL | fn take_baz(_: impl Baz) {}
    |                     ^^^ required by this bound in `take_baz`
 
 warning: malformed `on_unimplemented` attribute
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:15:50
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:17:50
    |
 LL | #[diagnostic::on_unimplemented(message = "Boom", on(_Self = "i32", message = "whatever"))]
    |                                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ invalid option found here
@@ -120,7 +120,7 @@ LL | #[diagnostic::on_unimplemented(message = "Boom", on(_Self = "i32", message
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error[E0277]: Boom
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:45:15
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:47:15
    |
 LL |     take_boom(1_i32);
    |     --------- ^^^^^ the trait `Boom` is not implemented for `i32`
@@ -128,18 +128,18 @@ LL |     take_boom(1_i32);
    |     required by a bound introduced by this call
    |
 help: this trait has no implementations, consider adding one
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:18:1
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:20:1
    |
 LL | trait Boom {}
    | ^^^^^^^^^^
 note: required by a bound in `take_boom`
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:36:22
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:38:22
    |
 LL | fn take_boom(_: impl Boom) {}
    |                      ^^^^ required by this bound in `take_boom`
 
 warning: missing options for `on_unimplemented` attribute
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:24:1
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:26:1
    |
 LL | #[diagnostic::on_unimplemented]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -148,7 +148,7 @@ LL | #[diagnostic::on_unimplemented]
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error[E0277]: the trait bound `i32: Whatever` is not satisfied
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:47:19
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:49:19
    |
 LL |     take_whatever(1_i32);
    |     ------------- ^^^^^ the trait `Whatever` is not implemented for `i32`
@@ -156,18 +156,18 @@ LL |     take_whatever(1_i32);
    |     required by a bound introduced by this call
    |
 help: this trait has no implementations, consider adding one
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:27:1
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:29:1
    |
 LL | trait Whatever {}
    | ^^^^^^^^^^^^^^
 note: required by a bound in `take_whatever`
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:37:26
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:39:26
    |
 LL | fn take_whatever(_: impl Whatever) {}
    |                          ^^^^^^^^ required by this bound in `take_whatever`
 
 warning: there is no parameter `DoesNotExist` on trait `Test`
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:29:32
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:31:32
    |
 LL | #[diagnostic::on_unimplemented(message = "{DoesNotExist}")]
    |                                ^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -176,7 +176,7 @@ LL | #[diagnostic::on_unimplemented(message = "{DoesNotExist}")]
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error[E0277]: {DoesNotExist}
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:49:15
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:51:15
    |
 LL |     take_test(());
    |     --------- ^^ the trait `Test` is not implemented for `()`
@@ -184,12 +184,12 @@ LL |     take_test(());
    |     required by a bound introduced by this call
    |
 help: this trait has no implementations, consider adding one
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:32:1
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:34:1
    |
 LL | trait Test {}
    | ^^^^^^^^^^
 note: required by a bound in `take_test`
-  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:38:22
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:40:22
    |
 LL | fn take_test(_: impl Test) {}
    |                      ^^^^ required by this bound in `take_test`
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/error_is_shown_in_downstream_crates.rs b/tests/ui/diagnostic_namespace/on_unimplemented/error_is_shown_in_downstream_crates.rs
index 7eaff73dca1..dff209d4761 100644
--- a/tests/ui/diagnostic_namespace/on_unimplemented/error_is_shown_in_downstream_crates.rs
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/error_is_shown_in_downstream_crates.rs
@@ -1,4 +1,5 @@
 //@ aux-build:other.rs
+//@ reference: attributes.diagnostic.on_unimplemented.intro
 
 extern crate other;
 
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/error_is_shown_in_downstream_crates.stderr b/tests/ui/diagnostic_namespace/on_unimplemented/error_is_shown_in_downstream_crates.stderr
index a9968538d0d..c0dd6d9628a 100644
--- a/tests/ui/diagnostic_namespace/on_unimplemented/error_is_shown_in_downstream_crates.stderr
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/error_is_shown_in_downstream_crates.stderr
@@ -1,5 +1,5 @@
 error[E0277]: Message
-  --> $DIR/error_is_shown_in_downstream_crates.rs:10:14
+  --> $DIR/error_is_shown_in_downstream_crates.rs:11:14
    |
 LL |     take_foo(());
    |     -------- ^^ label
@@ -9,7 +9,7 @@ LL |     take_foo(());
    = help: the trait `Foo` is not implemented for `()`
    = note: Note
 note: required by a bound in `take_foo`
-  --> $DIR/error_is_shown_in_downstream_crates.rs:7:21
+  --> $DIR/error_is_shown_in_downstream_crates.rs:8:21
    |
 LL | fn take_foo(_: impl Foo) {}
    |                     ^^^ required by this bound in `take_foo`
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/ignore_unsupported_options_and_continue_to_use_fallback.rs b/tests/ui/diagnostic_namespace/on_unimplemented/ignore_unsupported_options_and_continue_to_use_fallback.rs
index 5b25fb234bc..c638681173d 100644
--- a/tests/ui/diagnostic_namespace/on_unimplemented/ignore_unsupported_options_and_continue_to_use_fallback.rs
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/ignore_unsupported_options_and_continue_to_use_fallback.rs
@@ -1,3 +1,5 @@
+//@ reference: attributes.diagnostic.on_unimplemented.repetition
+//@ reference: attributes.diagnostic.on_unimplemented.syntax
 #[diagnostic::on_unimplemented(
     if(Self = "()"),
     //~^WARN malformed `on_unimplemented` attribute
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/ignore_unsupported_options_and_continue_to_use_fallback.stderr b/tests/ui/diagnostic_namespace/on_unimplemented/ignore_unsupported_options_and_continue_to_use_fallback.stderr
index 56d125e20e5..e00846da77b 100644
--- a/tests/ui/diagnostic_namespace/on_unimplemented/ignore_unsupported_options_and_continue_to_use_fallback.stderr
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/ignore_unsupported_options_and_continue_to_use_fallback.stderr
@@ -1,5 +1,5 @@
 warning: malformed `on_unimplemented` attribute
-  --> $DIR/ignore_unsupported_options_and_continue_to_use_fallback.rs:2:5
+  --> $DIR/ignore_unsupported_options_and_continue_to_use_fallback.rs:4:5
    |
 LL |     if(Self = "()"),
    |     ^^^^^^^^^^^^^^^ invalid option found here
@@ -8,7 +8,7 @@ LL |     if(Self = "()"),
    = note: `#[warn(unknown_or_malformed_diagnostic_attributes)]` on by default
 
 warning: `message` is ignored due to previous definition of `message`
-  --> $DIR/ignore_unsupported_options_and_continue_to_use_fallback.rs:8:32
+  --> $DIR/ignore_unsupported_options_and_continue_to_use_fallback.rs:10:32
    |
 LL |     message = "custom message",
    |     -------------------------- `message` is first declared here
@@ -17,7 +17,7 @@ LL | #[diagnostic::on_unimplemented(message = "fallback!!")]
    |                                ^^^^^^^^^^^^^^^^^^^^^^ `message` is already declared here
 
 warning: malformed `on_unimplemented` attribute
-  --> $DIR/ignore_unsupported_options_and_continue_to_use_fallback.rs:2:5
+  --> $DIR/ignore_unsupported_options_and_continue_to_use_fallback.rs:4:5
    |
 LL |     if(Self = "()"),
    |     ^^^^^^^^^^^^^^^ invalid option found here
@@ -26,7 +26,7 @@ LL |     if(Self = "()"),
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 warning: `message` is ignored due to previous definition of `message`
-  --> $DIR/ignore_unsupported_options_and_continue_to_use_fallback.rs:8:32
+  --> $DIR/ignore_unsupported_options_and_continue_to_use_fallback.rs:10:32
    |
 LL |     message = "custom message",
    |     -------------------------- `message` is first declared here
@@ -37,7 +37,7 @@ LL | #[diagnostic::on_unimplemented(message = "fallback!!")]
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error[E0277]: custom message
-  --> $DIR/ignore_unsupported_options_and_continue_to_use_fallback.rs:18:15
+  --> $DIR/ignore_unsupported_options_and_continue_to_use_fallback.rs:20:15
    |
 LL |     takes_foo(());
    |     --------- ^^ fallback label
@@ -48,12 +48,12 @@ LL |     takes_foo(());
    = note: custom note
    = note: fallback note
 help: this trait has no implementations, consider adding one
-  --> $DIR/ignore_unsupported_options_and_continue_to_use_fallback.rs:13:1
+  --> $DIR/ignore_unsupported_options_and_continue_to_use_fallback.rs:15:1
    |
 LL | trait Foo {}
    | ^^^^^^^^^
 note: required by a bound in `takes_foo`
-  --> $DIR/ignore_unsupported_options_and_continue_to_use_fallback.rs:15:22
+  --> $DIR/ignore_unsupported_options_and_continue_to_use_fallback.rs:17:22
    |
 LL | fn takes_foo(_: impl Foo) {}
    |                      ^^^ required by this bound in `takes_foo`
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/multiple_notes.rs b/tests/ui/diagnostic_namespace/on_unimplemented/multiple_notes.rs
index a5982f6492c..dc0f850031e 100644
--- a/tests/ui/diagnostic_namespace/on_unimplemented/multiple_notes.rs
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/multiple_notes.rs
@@ -1,3 +1,4 @@
+//@ reference: attributes.diagnostic.on_unimplemented.note-repetition
 #[diagnostic::on_unimplemented(message = "Foo", label = "Bar", note = "Baz", note = "Boom")]
 trait Foo {}
 
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/multiple_notes.stderr b/tests/ui/diagnostic_namespace/on_unimplemented/multiple_notes.stderr
index 93a0d0b3f41..6567269be3b 100644
--- a/tests/ui/diagnostic_namespace/on_unimplemented/multiple_notes.stderr
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/multiple_notes.stderr
@@ -1,5 +1,5 @@
 error[E0277]: Foo
-  --> $DIR/multiple_notes.rs:12:15
+  --> $DIR/multiple_notes.rs:13:15
    |
 LL |     takes_foo(());
    |     --------- ^^ Bar
@@ -10,18 +10,18 @@ LL |     takes_foo(());
    = note: Baz
    = note: Boom
 help: this trait has no implementations, consider adding one
-  --> $DIR/multiple_notes.rs:2:1
+  --> $DIR/multiple_notes.rs:3:1
    |
 LL | trait Foo {}
    | ^^^^^^^^^
 note: required by a bound in `takes_foo`
-  --> $DIR/multiple_notes.rs:8:22
+  --> $DIR/multiple_notes.rs:9:22
    |
 LL | fn takes_foo(_: impl Foo) {}
    |                      ^^^ required by this bound in `takes_foo`
 
 error[E0277]: Bar
-  --> $DIR/multiple_notes.rs:14:15
+  --> $DIR/multiple_notes.rs:15:15
    |
 LL |     takes_bar(());
    |     --------- ^^ Foo
@@ -32,12 +32,12 @@ LL |     takes_bar(());
    = note: Baz
    = note: Baz2
 help: this trait has no implementations, consider adding one
-  --> $DIR/multiple_notes.rs:6:1
+  --> $DIR/multiple_notes.rs:7:1
    |
 LL | trait Bar {}
    | ^^^^^^^^^
 note: required by a bound in `takes_bar`
-  --> $DIR/multiple_notes.rs:9:22
+  --> $DIR/multiple_notes.rs:10:22
    |
 LL | fn takes_bar(_: impl Bar) {}
    |                      ^^^ required by this bound in `takes_bar`
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/on_unimplemented_simple.rs b/tests/ui/diagnostic_namespace/on_unimplemented/on_unimplemented_simple.rs
index 7ca03127759..e584077c643 100644
--- a/tests/ui/diagnostic_namespace/on_unimplemented/on_unimplemented_simple.rs
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/on_unimplemented_simple.rs
@@ -1,3 +1,5 @@
+//@ reference: attributes.diagnostic.on_unimplemented.intro
+//@ reference: attributes.diagnostic.on_unimplemented.keys
 #[diagnostic::on_unimplemented(message = "Foo", label = "Bar", note = "Baz")]
 trait Foo {}
 
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/on_unimplemented_simple.stderr b/tests/ui/diagnostic_namespace/on_unimplemented/on_unimplemented_simple.stderr
index 6b17f40c6dd..de57f7044bf 100644
--- a/tests/ui/diagnostic_namespace/on_unimplemented/on_unimplemented_simple.stderr
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/on_unimplemented_simple.stderr
@@ -1,5 +1,5 @@
 error[E0277]: Foo
-  --> $DIR/on_unimplemented_simple.rs:7:15
+  --> $DIR/on_unimplemented_simple.rs:9:15
    |
 LL |     takes_foo(());
    |     --------- ^^ Bar
@@ -9,12 +9,12 @@ LL |     takes_foo(());
    = help: the trait `Foo` is not implemented for `()`
    = note: Baz
 help: this trait has no implementations, consider adding one
-  --> $DIR/on_unimplemented_simple.rs:2:1
+  --> $DIR/on_unimplemented_simple.rs:4:1
    |
 LL | trait Foo {}
    | ^^^^^^^^^
 note: required by a bound in `takes_foo`
-  --> $DIR/on_unimplemented_simple.rs:4:22
+  --> $DIR/on_unimplemented_simple.rs:6:22
    |
 LL | fn takes_foo(_: impl Foo) {}
    |                      ^^^ required by this bound in `takes_foo`
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/report_warning_on_duplicated_options.rs b/tests/ui/diagnostic_namespace/on_unimplemented/report_warning_on_duplicated_options.rs
index 8c0b8150417..d0eb608c40f 100644
--- a/tests/ui/diagnostic_namespace/on_unimplemented/report_warning_on_duplicated_options.rs
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/report_warning_on_duplicated_options.rs
@@ -1,3 +1,4 @@
+//@ reference: attributes.diagnostic.on_unimplemented.repetition
 #[diagnostic::on_unimplemented(
     message = "first message",
     label = "first label",
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/report_warning_on_duplicated_options.stderr b/tests/ui/diagnostic_namespace/on_unimplemented/report_warning_on_duplicated_options.stderr
index 43ab6bf25a1..feafe2cee76 100644
--- a/tests/ui/diagnostic_namespace/on_unimplemented/report_warning_on_duplicated_options.stderr
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/report_warning_on_duplicated_options.stderr
@@ -1,5 +1,5 @@
 warning: `message` is ignored due to previous definition of `message`
-  --> $DIR/report_warning_on_duplicated_options.rs:7:5
+  --> $DIR/report_warning_on_duplicated_options.rs:8:5
    |
 LL |     message = "first message",
    |     ------------------------- `message` is first declared here
@@ -10,7 +10,7 @@ LL |     message = "second message",
    = note: `#[warn(unknown_or_malformed_diagnostic_attributes)]` on by default
 
 warning: `label` is ignored due to previous definition of `label`
-  --> $DIR/report_warning_on_duplicated_options.rs:10:5
+  --> $DIR/report_warning_on_duplicated_options.rs:11:5
    |
 LL |     label = "first label",
    |     --------------------- `label` is first declared here
@@ -19,7 +19,7 @@ LL |     label = "second label",
    |     ^^^^^^^^^^^^^^^^^^^^^^ `label` is already declared here
 
 warning: `message` is ignored due to previous definition of `message`
-  --> $DIR/report_warning_on_duplicated_options.rs:7:5
+  --> $DIR/report_warning_on_duplicated_options.rs:8:5
    |
 LL |     message = "first message",
    |     ------------------------- `message` is first declared here
@@ -30,7 +30,7 @@ LL |     message = "second message",
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 warning: `label` is ignored due to previous definition of `label`
-  --> $DIR/report_warning_on_duplicated_options.rs:10:5
+  --> $DIR/report_warning_on_duplicated_options.rs:11:5
    |
 LL |     label = "first label",
    |     --------------------- `label` is first declared here
@@ -41,7 +41,7 @@ LL |     label = "second label",
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error[E0277]: first message
-  --> $DIR/report_warning_on_duplicated_options.rs:21:15
+  --> $DIR/report_warning_on_duplicated_options.rs:22:15
    |
 LL |     takes_foo(());
    |     --------- ^^ first label
@@ -52,12 +52,12 @@ LL |     takes_foo(());
    = note: custom note
    = note: second note
 help: this trait has no implementations, consider adding one
-  --> $DIR/report_warning_on_duplicated_options.rs:15:1
+  --> $DIR/report_warning_on_duplicated_options.rs:16:1
    |
 LL | trait Foo {}
    | ^^^^^^^^^
 note: required by a bound in `takes_foo`
-  --> $DIR/report_warning_on_duplicated_options.rs:18:22
+  --> $DIR/report_warning_on_duplicated_options.rs:19:22
    |
 LL | fn takes_foo(_: impl Foo) {}
    |                      ^^^ required by this bound in `takes_foo`
diff --git a/tests/ui/diagnostic_namespace/suggest_typos.rs b/tests/ui/diagnostic_namespace/suggest_typos.rs
index b25f097a8ad..6fa4f800462 100644
--- a/tests/ui/diagnostic_namespace/suggest_typos.rs
+++ b/tests/ui/diagnostic_namespace/suggest_typos.rs
@@ -1,3 +1,4 @@
+//@ reference: attributes.diagnostic.namespace.unknown-invalid-syntax
 #![deny(unknown_or_malformed_diagnostic_attributes)]
 
 #[diagnostic::onunimplemented]
diff --git a/tests/ui/diagnostic_namespace/suggest_typos.stderr b/tests/ui/diagnostic_namespace/suggest_typos.stderr
index 307311258f2..ff4ee9717d4 100644
--- a/tests/ui/diagnostic_namespace/suggest_typos.stderr
+++ b/tests/ui/diagnostic_namespace/suggest_typos.stderr
@@ -1,11 +1,11 @@
 error: unknown diagnostic attribute
-  --> $DIR/suggest_typos.rs:3:15
+  --> $DIR/suggest_typos.rs:4:15
    |
 LL | #[diagnostic::onunimplemented]
    |               ^^^^^^^^^^^^^^^
    |
 note: the lint level is defined here
-  --> $DIR/suggest_typos.rs:1:9
+  --> $DIR/suggest_typos.rs:2:9
    |
 LL | #![deny(unknown_or_malformed_diagnostic_attributes)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -15,7 +15,7 @@ LL | #[diagnostic::on_unimplemented]
    |               ~~~~~~~~~~~~~~~~
 
 error: unknown diagnostic attribute
-  --> $DIR/suggest_typos.rs:8:15
+  --> $DIR/suggest_typos.rs:9:15
    |
 LL | #[diagnostic::un_onimplemented]
    |               ^^^^^^^^^^^^^^^^
@@ -26,7 +26,7 @@ LL | #[diagnostic::on_unimplemented]
    |               ~~~~~~~~~~~~~~~~
 
 error: unknown diagnostic attribute
-  --> $DIR/suggest_typos.rs:13:15
+  --> $DIR/suggest_typos.rs:14:15
    |
 LL | #[diagnostic::on_implemented]
    |               ^^^^^^^^^^^^^^
diff --git a/tests/ui/traits/negative-bounds/on-unimplemented.rs b/tests/ui/traits/negative-bounds/on-unimplemented.rs
index 34582590861..5f2a705ed56 100644
--- a/tests/ui/traits/negative-bounds/on-unimplemented.rs
+++ b/tests/ui/traits/negative-bounds/on-unimplemented.rs
@@ -1,3 +1,5 @@
+//@ reference: attributes.diagnostic.on_unimplemented.intro
+
 #![feature(negative_bounds)]
 
 #[diagnostic::on_unimplemented(message = "this ain't fooing")]
diff --git a/tests/ui/traits/negative-bounds/on-unimplemented.stderr b/tests/ui/traits/negative-bounds/on-unimplemented.stderr
index ed473d57917..8a295611010 100644
--- a/tests/ui/traits/negative-bounds/on-unimplemented.stderr
+++ b/tests/ui/traits/negative-bounds/on-unimplemented.stderr
@@ -1,5 +1,5 @@
 error[E0277]: the trait bound `NotFoo: !Foo` is not satisfied
-  --> $DIR/on-unimplemented.rs:7:15
+  --> $DIR/on-unimplemented.rs:9:15
    |
 LL | fn hello() -> impl !Foo {
    |               ^^^^^^^^^ the trait bound `NotFoo: !Foo` is not satisfied