rustc_lint: Prevent triplication of 'unknown lint' lint

19 files changed, 42 insertions, 392 deletions

diff --git a/compiler/rustc_lint/src/levels.rs b/compiler/rustc_lint/src/levels.rs
index c781033a261..c229728cb79 100644
--- a/compiler/rustc_lint/src/levels.rs
+++ b/compiler/rustc_lint/src/levels.rs
@@ -1054,33 +1054,33 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
     /// Checks if the lint is gated on a feature that is not enabled.
     ///
     /// Returns `true` if the lint's feature is enabled.
-    // FIXME only emit this once for each attribute, instead of repeating it 4 times for
-    // pre-expansion lints, post-expansion lints, `shallow_lint_levels_on` and `lint_expectations`.
     #[track_caller]
     fn check_gated_lint(&self, lint_id: LintId, span: Span, lint_from_cli: bool) -> bool {
         if let Some(feature) = lint_id.lint.feature_gate {
             if !self.features.active(feature) {
-                let lint = builtin::UNKNOWN_LINTS;
-                let (level, src) = self.lint_level(builtin::UNKNOWN_LINTS);
-                struct_lint_level(
-                    self.sess,
-                    lint,
-                    level,
-                    src,
-                    Some(span.into()),
-                    fluent::lint_unknown_gated_lint,
-                    |lint| {
-                        lint.set_arg("name", lint_id.lint.name_lower());
-                        lint.note(fluent::lint_note);
-                        rustc_session::parse::add_feature_diagnostics_for_issue(
-                            lint,
-                            &self.sess.parse_sess,
-                            feature,
-                            GateIssue::Language,
-                            lint_from_cli,
-                        );
-                    },
-                );
+                if self.lint_added_lints {
+                    let lint = builtin::UNKNOWN_LINTS;
+                    let (level, src) = self.lint_level(builtin::UNKNOWN_LINTS);
+                    struct_lint_level(
+                        self.sess,
+                        lint,
+                        level,
+                        src,
+                        Some(span.into()),
+                        fluent::lint_unknown_gated_lint,
+                        |lint| {
+                            lint.set_arg("name", lint_id.lint.name_lower());
+                            lint.note(fluent::lint_note);
+                            rustc_session::parse::add_feature_diagnostics_for_issue(
+                                lint,
+                                &self.sess.parse_sess,
+                                feature,
+                                GateIssue::Language,
+                                lint_from_cli,
+                            );
+                        },
+                    );
+                }
                 return false;
             }
         }
diff --git a/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.rs b/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.rs
index 0467dea621b..4e296b96ca9 100644
--- a/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.rs
+++ b/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.rs
@@ -2,11 +2,7 @@
 
 #![deny(multiple_supertrait_upcastable)]
 //~^ WARNING unknown lint: `multiple_supertrait_upcastable`
-//~| WARNING unknown lint: `multiple_supertrait_upcastable`
-//~| WARNING unknown lint: `multiple_supertrait_upcastable`
 #![warn(multiple_supertrait_upcastable)]
 //~^ WARNING unknown lint: `multiple_supertrait_upcastable`
-//~| WARNING unknown lint: `multiple_supertrait_upcastable`
-//~| WARNING unknown lint: `multiple_supertrait_upcastable`
 
 fn main() {}
diff --git a/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.stderr b/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.stderr
index 5e14bf6397f..f6fcf4ee3ed 100644
--- a/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.stderr
+++ b/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.stderr
@@ -9,7 +9,7 @@ LL | #![deny(multiple_supertrait_upcastable)]
    = note: `#[warn(unknown_lints)]` on by default
 
 warning: unknown lint: `multiple_supertrait_upcastable`
-  --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:7:1
+  --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:5:1
    |
 LL | #![warn(multiple_supertrait_upcastable)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -17,45 +17,5 @@ LL | #![warn(multiple_supertrait_upcastable)]
    = note: the `multiple_supertrait_upcastable` lint is unstable
    = help: add `#![feature(multiple_supertrait_upcastable)]` to the crate attributes to enable
 
-warning: unknown lint: `multiple_supertrait_upcastable`
-  --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:3:1
-   |
-LL | #![deny(multiple_supertrait_upcastable)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `multiple_supertrait_upcastable` lint is unstable
-   = help: add `#![feature(multiple_supertrait_upcastable)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `multiple_supertrait_upcastable`
-  --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:7:1
-   |
-LL | #![warn(multiple_supertrait_upcastable)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `multiple_supertrait_upcastable` lint is unstable
-   = help: add `#![feature(multiple_supertrait_upcastable)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `multiple_supertrait_upcastable`
-  --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:3:1
-   |
-LL | #![deny(multiple_supertrait_upcastable)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `multiple_supertrait_upcastable` lint is unstable
-   = help: add `#![feature(multiple_supertrait_upcastable)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `multiple_supertrait_upcastable`
-  --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:7:1
-   |
-LL | #![warn(multiple_supertrait_upcastable)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `multiple_supertrait_upcastable` lint is unstable
-   = help: add `#![feature(multiple_supertrait_upcastable)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: 6 warnings emitted
+warning: 2 warnings emitted
 
diff --git a/tests/ui/feature-gates/feature-gate-non_exhaustive_omitted_patterns_lint.rs b/tests/ui/feature-gates/feature-gate-non_exhaustive_omitted_patterns_lint.rs
index 1922bfb4913..1db3c2ccdde 100644
--- a/tests/ui/feature-gates/feature-gate-non_exhaustive_omitted_patterns_lint.rs
+++ b/tests/ui/feature-gates/feature-gate-non_exhaustive_omitted_patterns_lint.rs
@@ -2,12 +2,8 @@
 
 #![deny(non_exhaustive_omitted_patterns)]
 //~^ WARNING unknown lint: `non_exhaustive_omitted_patterns`
-//~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
-//~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
 #![allow(non_exhaustive_omitted_patterns)]
 //~^ WARNING unknown lint: `non_exhaustive_omitted_patterns`
-//~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
-//~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
 
 fn main() {
     enum Foo {
@@ -19,9 +15,6 @@ fn main() {
     #[allow(non_exhaustive_omitted_patterns)]
     //~^ WARNING unknown lint: `non_exhaustive_omitted_patterns`
     //~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
-    //~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
-    //~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
-    //~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
     match Foo::A {
         //~^ ERROR non-exhaustive patterns: `Foo::C` not covered
         Foo::A => {}
@@ -31,9 +24,6 @@ fn main() {
     #[warn(non_exhaustive_omitted_patterns)]
     //~^ WARNING unknown lint: `non_exhaustive_omitted_patterns`
     //~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
-    //~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
-    //~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
-    //~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
     match Foo::A {
         Foo::A => {}
         Foo::B => {}
diff --git a/tests/ui/feature-gates/feature-gate-non_exhaustive_omitted_patterns_lint.stderr b/tests/ui/feature-gates/feature-gate-non_exhaustive_omitted_patterns_lint.stderr
index a5333713977..955d7fe3f3e 100644
--- a/tests/ui/feature-gates/feature-gate-non_exhaustive_omitted_patterns_lint.stderr
+++ b/tests/ui/feature-gates/feature-gate-non_exhaustive_omitted_patterns_lint.stderr
@@ -10,7 +10,7 @@ LL | #![deny(non_exhaustive_omitted_patterns)]
    = note: `#[warn(unknown_lints)]` on by default
 
 warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:7:1
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:5:1
    |
 LL | #![allow(non_exhaustive_omitted_patterns)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -20,7 +20,7 @@ LL | #![allow(non_exhaustive_omitted_patterns)]
    = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
 
 warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:19:5
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:15:5
    |
 LL |     #[allow(non_exhaustive_omitted_patterns)]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -30,7 +30,7 @@ LL |     #[allow(non_exhaustive_omitted_patterns)]
    = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
 
 warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:19:5
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:15:5
    |
 LL |     #[allow(non_exhaustive_omitted_patterns)]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -41,7 +41,7 @@ LL |     #[allow(non_exhaustive_omitted_patterns)]
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:31:5
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:24:5
    |
 LL |     #[warn(non_exhaustive_omitted_patterns)]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -51,73 +51,7 @@ LL |     #[warn(non_exhaustive_omitted_patterns)]
    = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
 
 warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:31:5
-   |
-LL |     #[warn(non_exhaustive_omitted_patterns)]
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `non_exhaustive_omitted_patterns` lint is unstable
-   = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
-   = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:3:1
-   |
-LL | #![deny(non_exhaustive_omitted_patterns)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `non_exhaustive_omitted_patterns` lint is unstable
-   = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
-   = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:7:1
-   |
-LL | #![allow(non_exhaustive_omitted_patterns)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `non_exhaustive_omitted_patterns` lint is unstable
-   = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
-   = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:19:5
-   |
-LL |     #[allow(non_exhaustive_omitted_patterns)]
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `non_exhaustive_omitted_patterns` lint is unstable
-   = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
-   = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:19:5
-   |
-LL |     #[allow(non_exhaustive_omitted_patterns)]
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `non_exhaustive_omitted_patterns` lint is unstable
-   = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
-   = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:31:5
-   |
-LL |     #[warn(non_exhaustive_omitted_patterns)]
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `non_exhaustive_omitted_patterns` lint is unstable
-   = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
-   = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:31:5
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:24:5
    |
 LL |     #[warn(non_exhaustive_omitted_patterns)]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -128,13 +62,13 @@ LL |     #[warn(non_exhaustive_omitted_patterns)]
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error[E0004]: non-exhaustive patterns: `Foo::C` not covered
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:25:11
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:18:11
    |
 LL |     match Foo::A {
    |           ^^^^^^ pattern `Foo::C` not covered
    |
 note: `Foo` defined here
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:13:10
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:9:10
    |
 LL |     enum Foo {
    |          ^^^
@@ -148,50 +82,6 @@ LL ~         Foo::B => {},
 LL +         Foo::C => todo!()
    |
 
-warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:3:1
-   |
-LL | #![deny(non_exhaustive_omitted_patterns)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `non_exhaustive_omitted_patterns` lint is unstable
-   = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
-   = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:7:1
-   |
-LL | #![allow(non_exhaustive_omitted_patterns)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `non_exhaustive_omitted_patterns` lint is unstable
-   = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
-   = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:19:5
-   |
-LL |     #[allow(non_exhaustive_omitted_patterns)]
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `non_exhaustive_omitted_patterns` lint is unstable
-   = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
-   = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:31:5
-   |
-LL |     #[warn(non_exhaustive_omitted_patterns)]
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `non_exhaustive_omitted_patterns` lint is unstable
-   = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
-   = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-error: aborting due to 1 previous error; 16 warnings emitted
+error: aborting due to 1 previous error; 6 warnings emitted
 
 For more information about this error, try `rustc --explain E0004`.
diff --git a/tests/ui/feature-gates/feature-gate-strict_provenance.rs b/tests/ui/feature-gates/feature-gate-strict_provenance.rs
index 75d0ee5700d..24b8369b3d8 100644
--- a/tests/ui/feature-gates/feature-gate-strict_provenance.rs
+++ b/tests/ui/feature-gates/feature-gate-strict_provenance.rs
@@ -2,12 +2,8 @@
 
 #![deny(fuzzy_provenance_casts)]
 //~^ WARNING unknown lint: `fuzzy_provenance_casts`
-//~| WARNING unknown lint: `fuzzy_provenance_casts`
-//~| WARNING unknown lint: `fuzzy_provenance_casts`
 #![deny(lossy_provenance_casts)]
 //~^ WARNING unknown lint: `lossy_provenance_casts`
-//~| WARNING unknown lint: `lossy_provenance_casts`
-//~| WARNING unknown lint: `lossy_provenance_casts`
 
 fn main() {
     // no warnings emitted since the lints are not activated
diff --git a/tests/ui/feature-gates/feature-gate-strict_provenance.stderr b/tests/ui/feature-gates/feature-gate-strict_provenance.stderr
index 1e6d762a540..36224ee864b 100644
--- a/tests/ui/feature-gates/feature-gate-strict_provenance.stderr
+++ b/tests/ui/feature-gates/feature-gate-strict_provenance.stderr
@@ -10,7 +10,7 @@ LL | #![deny(fuzzy_provenance_casts)]
    = note: `#[warn(unknown_lints)]` on by default
 
 warning: unknown lint: `lossy_provenance_casts`
-  --> $DIR/feature-gate-strict_provenance.rs:7:1
+  --> $DIR/feature-gate-strict_provenance.rs:5:1
    |
 LL | #![deny(lossy_provenance_casts)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -19,49 +19,5 @@ LL | #![deny(lossy_provenance_casts)]
    = note: see issue #95228 <https://github.com/rust-lang/rust/issues/95228> for more information
    = help: add `#![feature(strict_provenance)]` to the crate attributes to enable
 
-warning: unknown lint: `fuzzy_provenance_casts`
-  --> $DIR/feature-gate-strict_provenance.rs:3:1
-   |
-LL | #![deny(fuzzy_provenance_casts)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `fuzzy_provenance_casts` lint is unstable
-   = note: see issue #95228 <https://github.com/rust-lang/rust/issues/95228> for more information
-   = help: add `#![feature(strict_provenance)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `lossy_provenance_casts`
-  --> $DIR/feature-gate-strict_provenance.rs:7:1
-   |
-LL | #![deny(lossy_provenance_casts)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `lossy_provenance_casts` lint is unstable
-   = note: see issue #95228 <https://github.com/rust-lang/rust/issues/95228> for more information
-   = help: add `#![feature(strict_provenance)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `fuzzy_provenance_casts`
-  --> $DIR/feature-gate-strict_provenance.rs:3:1
-   |
-LL | #![deny(fuzzy_provenance_casts)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `fuzzy_provenance_casts` lint is unstable
-   = note: see issue #95228 <https://github.com/rust-lang/rust/issues/95228> for more information
-   = help: add `#![feature(strict_provenance)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `lossy_provenance_casts`
-  --> $DIR/feature-gate-strict_provenance.rs:7:1
-   |
-LL | #![deny(lossy_provenance_casts)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `lossy_provenance_casts` lint is unstable
-   = note: see issue #95228 <https://github.com/rust-lang/rust/issues/95228> for more information
-   = help: add `#![feature(strict_provenance)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: 6 warnings emitted
+warning: 2 warnings emitted
 
diff --git a/tests/ui/feature-gates/feature-gate-test_unstable_lint.rs b/tests/ui/feature-gates/feature-gate-test_unstable_lint.rs
index c398394cbe1..3882ba9a227 100644
--- a/tests/ui/feature-gates/feature-gate-test_unstable_lint.rs
+++ b/tests/ui/feature-gates/feature-gate-test_unstable_lint.rs
@@ -3,7 +3,5 @@
 // `test_unstable_lint` is for testing and should never be stabilized.
 #![allow(test_unstable_lint)]
 //~^ WARNING unknown lint: `test_unstable_lint`
-//~| WARNING unknown lint: `test_unstable_lint`
-//~| WARNING unknown lint: `test_unstable_lint`
 
 fn main() {}
diff --git a/tests/ui/feature-gates/feature-gate-test_unstable_lint.stderr b/tests/ui/feature-gates/feature-gate-test_unstable_lint.stderr
index 562aa478a93..aec32ac4abb 100644
--- a/tests/ui/feature-gates/feature-gate-test_unstable_lint.stderr
+++ b/tests/ui/feature-gates/feature-gate-test_unstable_lint.stderr
@@ -8,25 +8,5 @@ LL | #![allow(test_unstable_lint)]
    = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
    = note: `#[warn(unknown_lints)]` on by default
 
-warning: unknown lint: `test_unstable_lint`
-  --> $DIR/feature-gate-test_unstable_lint.rs:4:1
-   |
-LL | #![allow(test_unstable_lint)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `test_unstable_lint` lint is unstable
-   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `test_unstable_lint`
-  --> $DIR/feature-gate-test_unstable_lint.rs:4:1
-   |
-LL | #![allow(test_unstable_lint)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `test_unstable_lint` lint is unstable
-   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: 3 warnings emitted
+warning: 1 warning emitted
 
diff --git a/tests/ui/feature-gates/feature-gate-type_privacy_lints.rs b/tests/ui/feature-gates/feature-gate-type_privacy_lints.rs
index 8bb9736f1b4..80e51b265db 100644
--- a/tests/ui/feature-gates/feature-gate-type_privacy_lints.rs
+++ b/tests/ui/feature-gates/feature-gate-type_privacy_lints.rs
@@ -1,6 +1,4 @@
 // check-pass
 
 #![warn(unnameable_types)] //~ WARN unknown lint
-                           //~| WARN unknown lint
-                           //~| WARN unknown lint
 fn main() {}
diff --git a/tests/ui/feature-gates/feature-gate-type_privacy_lints.stderr b/tests/ui/feature-gates/feature-gate-type_privacy_lints.stderr
index 2614f2b3c35..5cc30de9c57 100644
--- a/tests/ui/feature-gates/feature-gate-type_privacy_lints.stderr
+++ b/tests/ui/feature-gates/feature-gate-type_privacy_lints.stderr
@@ -9,27 +9,5 @@ LL | #![warn(unnameable_types)]
    = help: add `#![feature(type_privacy_lints)]` to the crate attributes to enable
    = note: `#[warn(unknown_lints)]` on by default
 
-warning: unknown lint: `unnameable_types`
-  --> $DIR/feature-gate-type_privacy_lints.rs:3:1
-   |
-LL | #![warn(unnameable_types)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `unnameable_types` lint is unstable
-   = note: see issue #48054 <https://github.com/rust-lang/rust/issues/48054> for more information
-   = help: add `#![feature(type_privacy_lints)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `unnameable_types`
-  --> $DIR/feature-gate-type_privacy_lints.rs:3:1
-   |
-LL | #![warn(unnameable_types)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `unnameable_types` lint is unstable
-   = note: see issue #48054 <https://github.com/rust-lang/rust/issues/48054> for more information
-   = help: add `#![feature(type_privacy_lints)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: 3 warnings emitted
+warning: 1 warning emitted
 
diff --git a/tests/ui/lint/must_not_suspend/gated.rs b/tests/ui/lint/must_not_suspend/gated.rs
index b73a7655529..fe8192b0eaa 100644
--- a/tests/ui/lint/must_not_suspend/gated.rs
+++ b/tests/ui/lint/must_not_suspend/gated.rs
@@ -3,8 +3,6 @@
 // edition:2018
 #![deny(must_not_suspend)]
 //~^ WARNING unknown lint: `must_not_suspend`
-//~| WARNING unknown lint: `must_not_suspend`
-//~| WARNING unknown lint: `must_not_suspend`
 
 async fn other() {}
 
diff --git a/tests/ui/lint/must_not_suspend/gated.stderr b/tests/ui/lint/must_not_suspend/gated.stderr
index f0d2117d42b..c238c1f3351 100644
--- a/tests/ui/lint/must_not_suspend/gated.stderr
+++ b/tests/ui/lint/must_not_suspend/gated.stderr
@@ -9,27 +9,5 @@ LL | #![deny(must_not_suspend)]
    = help: add `#![feature(must_not_suspend)]` to the crate attributes to enable
    = note: `#[warn(unknown_lints)]` on by default
 
-warning: unknown lint: `must_not_suspend`
-  --> $DIR/gated.rs:4:1
-   |
-LL | #![deny(must_not_suspend)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `must_not_suspend` lint is unstable
-   = note: see issue #83310 <https://github.com/rust-lang/rust/issues/83310> for more information
-   = help: add `#![feature(must_not_suspend)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `must_not_suspend`
-  --> $DIR/gated.rs:4:1
-   |
-LL | #![deny(must_not_suspend)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `must_not_suspend` lint is unstable
-   = note: see issue #83310 <https://github.com/rust-lang/rust/issues/83310> for more information
-   = help: add `#![feature(must_not_suspend)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: 3 warnings emitted
+warning: 1 warning emitted
 
diff --git a/tests/ui/unknown-unstable-lints/deny-unstable-lint-command-line.stderr b/tests/ui/unknown-unstable-lints/deny-unstable-lint-command-line.stderr
index f0450aea49a..df83c103084 100644
--- a/tests/ui/unknown-unstable-lints/deny-unstable-lint-command-line.stderr
+++ b/tests/ui/unknown-unstable-lints/deny-unstable-lint-command-line.stderr
@@ -4,17 +4,5 @@ error: unknown lint: `test_unstable_lint`
    = help: add `-Zcrate-attr="feature(test_unstable_lint)"` to the command-line options to enable
    = note: requested on the command line with `-D unknown-lints`
 
-error: unknown lint: `test_unstable_lint`
-   |
-   = note: the `test_unstable_lint` lint is unstable
-   = help: add `-Zcrate-attr="feature(test_unstable_lint)"` to the command-line options to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-error: unknown lint: `test_unstable_lint`
-   |
-   = note: the `test_unstable_lint` lint is unstable
-   = help: add `-Zcrate-attr="feature(test_unstable_lint)"` to the command-line options to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-error: aborting due to 3 previous errors
+error: aborting due to 1 previous error
 
diff --git a/tests/ui/unknown-unstable-lints/deny-unstable-lint-inline.rs b/tests/ui/unknown-unstable-lints/deny-unstable-lint-inline.rs
index c6c60b12d83..29c6547abc1 100644
--- a/tests/ui/unknown-unstable-lints/deny-unstable-lint-inline.rs
+++ b/tests/ui/unknown-unstable-lints/deny-unstable-lint-inline.rs
@@ -3,7 +3,5 @@
 #![deny(unknown_lints)]
 #![allow(test_unstable_lint)]
 //~^ ERROR unknown lint: `test_unstable_lint`
-//~| ERROR unknown lint: `test_unstable_lint`
-//~| ERROR unknown lint: `test_unstable_lint`
 
 fn main() {}
diff --git a/tests/ui/unknown-unstable-lints/deny-unstable-lint-inline.stderr b/tests/ui/unknown-unstable-lints/deny-unstable-lint-inline.stderr
index 20a36b28dc6..0afe3d55c98 100644
--- a/tests/ui/unknown-unstable-lints/deny-unstable-lint-inline.stderr
+++ b/tests/ui/unknown-unstable-lints/deny-unstable-lint-inline.stderr
@@ -12,25 +12,5 @@ note: the lint level is defined here
 LL | #![deny(unknown_lints)]
    |         ^^^^^^^^^^^^^
 
-error: unknown lint: `test_unstable_lint`
-  --> $DIR/deny-unstable-lint-inline.rs:4:1
-   |
-LL | #![allow(test_unstable_lint)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `test_unstable_lint` lint is unstable
-   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-error: unknown lint: `test_unstable_lint`
-  --> $DIR/deny-unstable-lint-inline.rs:4:1
-   |
-LL | #![allow(test_unstable_lint)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `test_unstable_lint` lint is unstable
-   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-error: aborting due to 3 previous errors
+error: aborting due to 1 previous error
 
diff --git a/tests/ui/unknown-unstable-lints/warn-unknown-unstable-lint-command-line.stderr b/tests/ui/unknown-unstable-lints/warn-unknown-unstable-lint-command-line.stderr
index a2deecf1caf..c133b880ebd 100644
--- a/tests/ui/unknown-unstable-lints/warn-unknown-unstable-lint-command-line.stderr
+++ b/tests/ui/unknown-unstable-lints/warn-unknown-unstable-lint-command-line.stderr
@@ -4,17 +4,5 @@ warning: unknown lint: `test_unstable_lint`
    = help: add `-Zcrate-attr="feature(test_unstable_lint)"` to the command-line options to enable
    = note: requested on the command line with `-W unknown-lints`
 
-warning: unknown lint: `test_unstable_lint`
-   |
-   = note: the `test_unstable_lint` lint is unstable
-   = help: add `-Zcrate-attr="feature(test_unstable_lint)"` to the command-line options to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `test_unstable_lint`
-   |
-   = note: the `test_unstable_lint` lint is unstable
-   = help: add `-Zcrate-attr="feature(test_unstable_lint)"` to the command-line options to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: 3 warnings emitted
+warning: 1 warning emitted
 
diff --git a/tests/ui/unknown-unstable-lints/warn-unknown-unstable-lint-inline.rs b/tests/ui/unknown-unstable-lints/warn-unknown-unstable-lint-inline.rs
index f4247e4569e..89db84e69f6 100644
--- a/tests/ui/unknown-unstable-lints/warn-unknown-unstable-lint-inline.rs
+++ b/tests/ui/unknown-unstable-lints/warn-unknown-unstable-lint-inline.rs
@@ -3,7 +3,5 @@
 #![warn(unknown_lints)]
 #![allow(test_unstable_lint)]
 //~^ WARNING unknown lint: `test_unstable_lint`
-//~| WARNING unknown lint: `test_unstable_lint`
-//~| WARNING unknown lint: `test_unstable_lint`
 
 fn main() {}
diff --git a/tests/ui/unknown-unstable-lints/warn-unknown-unstable-lint-inline.stderr b/tests/ui/unknown-unstable-lints/warn-unknown-unstable-lint-inline.stderr
index 12afb2e294a..48c83b49e29 100644
--- a/tests/ui/unknown-unstable-lints/warn-unknown-unstable-lint-inline.stderr
+++ b/tests/ui/unknown-unstable-lints/warn-unknown-unstable-lint-inline.stderr
@@ -12,25 +12,5 @@ note: the lint level is defined here
 LL | #![warn(unknown_lints)]
    |         ^^^^^^^^^^^^^
 
-warning: unknown lint: `test_unstable_lint`
-  --> $DIR/warn-unknown-unstable-lint-inline.rs:4:1
-   |
-LL | #![allow(test_unstable_lint)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `test_unstable_lint` lint is unstable
-   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: unknown lint: `test_unstable_lint`
-  --> $DIR/warn-unknown-unstable-lint-inline.rs:4:1
-   |
-LL | #![allow(test_unstable_lint)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: the `test_unstable_lint` lint is unstable
-   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-warning: 3 warnings emitted
+warning: 1 warning emitted