Add ui test for new duplicated_attributes lint

tests/ui/duplicated_attributes.rs

@@ -0,0 +1,17 @@
+#![warn(clippy::duplicated_attributes)]
+#![cfg(any(unix, windows))]
+#![allow(dead_code)]
+#![allow(dead_code)] //~ ERROR: duplicated attribute
+#![cfg(any(unix, windows))]
+//~^ ERROR: duplicated attribute
+//~| ERROR: duplicated attribute
+
+#[cfg(any(unix, windows, target_os = "linux"))]
+#[allow(dead_code)]
+#[allow(dead_code)] //~ ERROR: duplicated attribute
+#[cfg(any(unix, windows, target_os = "linux"))]
+//~^ ERROR: duplicated attribute
+//~| ERROR: duplicated attribute
+fn foo() {}
+
+fn main() {}

tests/ui/duplicated_attributes.stderr

@@ -0,0 +1,123 @@
+error: duplicated attribute
+  --> tests/ui/duplicated_attributes.rs:4:10
+   |
+LL | #![allow(dead_code)]
+   |          ^^^^^^^^^
+   |
+note: first defined here
+  --> tests/ui/duplicated_attributes.rs:3:10
+   |
+LL | #![allow(dead_code)]
+   |          ^^^^^^^^^
+help: remove this attribute
+  --> tests/ui/duplicated_attributes.rs:4:10
+   |
+LL | #![allow(dead_code)]
+   |          ^^^^^^^^^
+   = note: `-D clippy::duplicated-attributes` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::duplicated_attributes)]`
+
+error: duplicated attribute
+  --> tests/ui/duplicated_attributes.rs:5:12
+   |
+LL | #![cfg(any(unix, windows))]
+   |            ^^^^
+   |
+note: first defined here
+  --> tests/ui/duplicated_attributes.rs:2:12
+   |
+LL | #![cfg(any(unix, windows))]
+   |            ^^^^
+help: remove this attribute
+  --> tests/ui/duplicated_attributes.rs:5:12
+   |
+LL | #![cfg(any(unix, windows))]
+   |            ^^^^
+
+error: duplicated attribute
+  --> tests/ui/duplicated_attributes.rs:5:18
+   |
+LL | #![cfg(any(unix, windows))]
+   |                  ^^^^^^^
+   |
+note: first defined here
+  --> tests/ui/duplicated_attributes.rs:2:18
+   |
+LL | #![cfg(any(unix, windows))]
+   |                  ^^^^^^^
+help: remove this attribute
+  --> tests/ui/duplicated_attributes.rs:5:18
+   |
+LL | #![cfg(any(unix, windows))]
+   |                  ^^^^^^^
+
+error: duplicated attribute
+  --> tests/ui/duplicated_attributes.rs:11:9
+   |
+LL | #[allow(dead_code)]
+   |         ^^^^^^^^^
+   |
+note: first defined here
+  --> tests/ui/duplicated_attributes.rs:10:9
+   |
+LL | #[allow(dead_code)]
+   |         ^^^^^^^^^
+help: remove this attribute
+  --> tests/ui/duplicated_attributes.rs:11:9
+   |
+LL | #[allow(dead_code)]
+   |         ^^^^^^^^^
+
+error: duplicated attribute
+  --> tests/ui/duplicated_attributes.rs:12:11
+   |
+LL | #[cfg(any(unix, windows, target_os = "linux"))]
+   |           ^^^^
+   |
+note: first defined here
+  --> tests/ui/duplicated_attributes.rs:9:11
+   |
+LL | #[cfg(any(unix, windows, target_os = "linux"))]
+   |           ^^^^
+help: remove this attribute
+  --> tests/ui/duplicated_attributes.rs:12:11
+   |
+LL | #[cfg(any(unix, windows, target_os = "linux"))]
+   |           ^^^^
+
+error: duplicated attribute
+  --> tests/ui/duplicated_attributes.rs:12:17
+   |
+LL | #[cfg(any(unix, windows, target_os = "linux"))]
+   |                 ^^^^^^^
+   |
+note: first defined here
+  --> tests/ui/duplicated_attributes.rs:9:17
+   |
+LL | #[cfg(any(unix, windows, target_os = "linux"))]
+   |                 ^^^^^^^
+help: remove this attribute
+  --> tests/ui/duplicated_attributes.rs:12:17
+   |
+LL | #[cfg(any(unix, windows, target_os = "linux"))]
+   |                 ^^^^^^^
+
+error: duplicated attribute
+  --> tests/ui/duplicated_attributes.rs:12:26
+   |
+LL | #[cfg(any(unix, windows, target_os = "linux"))]
+   |                          ^^^^^^^^^^^^^^^^^^^
+   |
+note: first defined here
+  --> tests/ui/duplicated_attributes.rs:9:26
+   |
+LL | #[cfg(any(unix, windows, target_os = "linux"))]
+   |                          ^^^^^^^^^^^^^^^^^^^
+help: remove this attribute
+  --> tests/ui/duplicated_attributes.rs:12:26
+   |
+LL | #[cfg(any(unix, windows, target_os = "linux"))]
+   |                          ^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 7 previous errors
+