Use native duplicate attribute check

compiler/rustc_attr/src/builtin.rs

@@ -679,14 +679,6 @@ where
             continue;
         }
 
-        if let Some((_, span)) = &depr {
-            struct_span_err!(diagnostic, attr.span, E0550, "multiple deprecated attributes")
-                .span_label(attr.span, "repeated deprecation attribute")
-                .span_label(*span, "first deprecation attribute")
-                .emit();
-            break;
-        }
-
         // FIXME(jhpratt) remove this eventually
         if attr.has_name(sym::rustc_deprecated) {
             diagnostic

compiler/rustc_feature/src/builtin_attrs.rs

@@ -304,8 +304,7 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
             List: r#"/*opt*/ since = "version", /*opt*/ note = "reason""#,
             NameValueStr: "reason"
         ),
-        // This has special duplicate handling in E0550 to handle duplicates with rustc_deprecated
+        ErrorFollowing
-        DuplicatesOk
     ),
 
     // Crate properties:
@@ -463,10 +462,10 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
     // ==========================================================================
 
     ungated!(feature, CrateLevel, template!(List: "name1, name2, ..."), DuplicatesOk),
-    // DuplicatesOk since it has its own validation
+    // FIXME(jhpratt) remove this eventually
     ungated!(
         rustc_deprecated, Normal,
-        template!(List: r#"since = "version", note = "...""#), DuplicatesOk // See E0550
+        template!(List: r#"since = "version", note = "...""#), ErrorFollowing
     ),
     // DuplicatesOk since it has its own validation
     ungated!(

src/test/ui/deprecation/deprecation-sanity.rs

@@ -24,7 +24,7 @@ mod bogus_attribute_types_1 {
 }
 
 #[deprecated(since = "a", note = "b")]
-#[deprecated(since = "a", note = "b")] //~ ERROR multiple deprecated attributes
+#[deprecated(since = "a", note = "b")] //~ ERROR multiple `deprecated` attributes
 fn multiple1() { }
 
 #[deprecated(since = "a", since = "b", note = "c")] //~ ERROR multiple 'since' items

src/test/ui/deprecation/deprecation-sanity.stderr

@@ -1,3 +1,15 @@
+error: multiple `deprecated` attributes
+  --> $DIR/deprecation-sanity.rs:27:1
+   |
+LL | #[deprecated(since = "a", note = "b")]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove this attribute
+   |
+note: attribute also specified here
+  --> $DIR/deprecation-sanity.rs:26:1
+   |
+LL | #[deprecated(since = "a", note = "b")]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
 error[E0541]: unknown meta item 'reason'
   --> $DIR/deprecation-sanity.rs:4:43
    |
@@ -40,14 +52,6 @@ error[E0565]: item in `deprecated` must be a key/value pair
 LL |     #[deprecated("test")]
    |                  ^^^^^^
 
-error[E0550]: multiple deprecated attributes
-  --> $DIR/deprecation-sanity.rs:27:1
-   |
-LL | #[deprecated(since = "a", note = "b")]
-   | -------------------------------------- first deprecation attribute
-LL | #[deprecated(since = "a", note = "b")]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ repeated deprecation attribute
-
 error[E0538]: multiple 'since' items
   --> $DIR/deprecation-sanity.rs:30:27
    |
@@ -64,5 +68,5 @@ LL | #[deprecated = "hello"]
 
 error: aborting due to 10 previous errors
 
-Some errors have detailed explanations: E0538, E0541, E0550, E0551, E0565.
+Some errors have detailed explanations: E0538, E0541, E0551, E0565.
 For more information about an error, try `rustc --explain E0538`.

src/test/ui/stability-attribute/stability-attribute-sanity.rs

@@ -59,7 +59,7 @@ fn multiple3() { }
 
 #[stable(feature = "a", since = "b")] //~ ERROR invalid stability version found
 #[deprecated(since = "b", note = "text")]
-#[deprecated(since = "b", note = "text")] //~ ERROR multiple deprecated attributes
+#[deprecated(since = "b", note = "text")] //~ ERROR multiple `deprecated` attributes
 #[rustc_const_unstable(feature = "c", issue = "none")]
 #[rustc_const_unstable(feature = "d", issue = "none")] //~ ERROR multiple stability levels
 pub const fn multiple4() { }

src/test/ui/stability-attribute/stability-attribute-sanity.stderr

@@ -1,3 +1,15 @@
+error: multiple `deprecated` attributes
+  --> $DIR/stability-attribute-sanity.rs:62:1
+   |
+LL | #[deprecated(since = "b", note = "text")]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove this attribute
+   |
+note: attribute also specified here
+  --> $DIR/stability-attribute-sanity.rs:61:1
+   |
+LL | #[deprecated(since = "b", note = "text")]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
 error[E0541]: unknown meta item 'reason'
   --> $DIR/stability-attribute-sanity.rs:8:42
    |
@@ -82,14 +94,6 @@ error[E0544]: multiple stability levels
 LL | #[stable(feature = "a", since = "b")]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0550]: multiple deprecated attributes
-  --> $DIR/stability-attribute-sanity.rs:62:1
-   |
-LL | #[deprecated(since = "b", note = "text")]
-   | ----------------------------------------- first deprecation attribute
-LL | #[deprecated(since = "b", note = "text")]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ repeated deprecation attribute
-
 error[E0544]: multiple stability levels
   --> $DIR/stability-attribute-sanity.rs:64:1
    |
@@ -128,5 +132,5 @@ LL | #[stable(feature = "a", since = "1.0.0")]
 
 error: aborting due to 20 previous errors
 
-Some errors have detailed explanations: E0539, E0541, E0542, E0543, E0544, E0546, E0547, E0549, E0550.
+Some errors have detailed explanations: E0539, E0541, E0542, E0543, E0544, E0546, E0547, E0549.
 For more information about an error, try `rustc --explain E0539`.