Auto merge of #95960 - jhpratt:remove-rustc_deprecated, r=compiler-errors

Remove `#[rustc_deprecated]`

This removes `#[rustc_deprecated]` and introduces diagnostics to help users to the right direction (that being `#[deprecated]`). All uses of `#[rustc_deprecated]` have been converted. CI is expected to fail initially; this requires #95958, which includes converting `stdarch`.

I plan on following up in a short while (maybe a bootstrap cycle?) removing the diagnostics, as they're only intended to be short-term.

Author: bors

compiler/rustc_attr/src/builtin.rs

@@ -679,12 +679,12 @@ 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")
+        // FIXME(jhpratt) remove this eventually
+        if attr.has_name(sym::rustc_deprecated) {
+            diagnostic
+                .struct_span_err(attr.span, "`#[rustc_deprecated]` has been removed")
+                .help("use `#[deprecated]` instead")
                 .emit();
-            break;
         }
 
         let Some(meta) = attr.meta() else {
@@ -742,12 +742,24 @@ where
                                     continue 'outer;
                                 }
                             }
-                            // FIXME(jhpratt) remove this after a bootstrap occurs. Emitting an
-                            // error specific to the renaming would be a good idea as well.
+                            // FIXME(jhpratt) remove this eventually
                             sym::reason if attr.has_name(sym::rustc_deprecated) => {
                                 if !get(mi, &mut note) {
                                     continue 'outer;
                                 }
+
+                                let mut diag = diagnostic
+                                    .struct_span_err(mi.span, "`reason` has been renamed");
+                                match note {
+                                    Some(note) => diag.span_suggestion(
+                                        mi.span,
+                                        "use `note` instead",
+                                        format!("note = \"{note}\""),
+                                        Applicability::MachineApplicable,
+                                    ),
+                                    None => diag.span_help(mi.span, "use `note` instead"),
+                                };
+                                diag.emit();
                             }
                             sym::suggestion => {
                                 if !sess.features_untracked().deprecated_suggestion {

compiler/rustc_error_codes/src/error_codes/E0539.md

@@ -6,7 +6,7 @@ Erroneous code example:
 #![feature(staged_api)]
 #![stable(since = "1.0.0", feature = "test")]
 
-#[rustc_deprecated(reason)] // error!
+#[deprecated(note)] // error!
 #[unstable(feature = "deprecated_fn", issue = "123")]
 fn deprecated() {}
 
@@ -30,7 +30,7 @@ To fix these issues you need to give required key-value pairs.
 #![feature(staged_api)]
 #![stable(since = "1.0.0", feature = "test")]
 
-#[rustc_deprecated(since = "1.39.0", reason = "reason")] // ok!
+#[deprecated(since = "1.39.0", note = "reason")] // ok!
 #[unstable(feature = "deprecated_fn", issue = "123")]
 fn deprecated() {}
 

compiler/rustc_error_codes/src/error_codes/E0542.md

@@ -13,8 +13,8 @@ fn _stable_fn() {}
 const fn _stable_const_fn() {}
 
 #[stable(feature = "_deprecated_fn", since = "0.1.0")]
-#[rustc_deprecated(
-    reason = "explanation for deprecation"
+#[deprecated(
+    note = "explanation for deprecation"
 )] // invalid
 fn _deprecated_fn() {}
 ```
@@ -32,9 +32,9 @@ fn _stable_fn() {}
 const fn _stable_const_fn() {}
 
 #[stable(feature = "_deprecated_fn", since = "0.1.0")]
-#[rustc_deprecated(
+#[deprecated(
     since = "1.0.0",
-    reason = "explanation for deprecation"
+    note = "explanation for deprecation"
 )] // ok!
 fn _deprecated_fn() {}
 ```

compiler/rustc_error_codes/src/error_codes/E0543.md

@@ -1,4 +1,4 @@
-The `reason` value is missing in a stability attribute.
+The `note` value is missing in a stability attribute.
 
 Erroneous code example:
 
@@ -7,22 +7,22 @@ Erroneous code example:
 #![stable(since = "1.0.0", feature = "test")]
 
 #[stable(since = "0.1.0", feature = "_deprecated_fn")]
-#[rustc_deprecated(
+#[deprecated(
     since = "1.0.0"
 )] // invalid
 fn _deprecated_fn() {}
 ```
 
-To fix this issue, you need to provide the `reason` field. Example:
+To fix this issue, you need to provide the `note` field. Example:
 
 ```
 #![feature(staged_api)]
 #![stable(since = "1.0.0", feature = "test")]
 
 #[stable(since = "0.1.0", feature = "_deprecated_fn")]
-#[rustc_deprecated(
+#[deprecated(
     since = "1.0.0",
-    reason = "explanation for deprecation"
+    note = "explanation for deprecation"
 )] // ok!
 fn _deprecated_fn() {}
 ```

compiler/rustc_error_codes/src/error_codes/E0549.md

@@ -1,15 +1,15 @@
-A `rustc_deprecated` attribute wasn't paired with a `stable`/`unstable`
-attribute.
+A `deprecated` attribute wasn't paired with a `stable`/`unstable` attribute with
+`#![feature(staged_api)]` enabled.
 
 Erroneous code example:
 
 ```compile_fail,E0549
 #![feature(staged_api)]
 #![stable(since = "1.0.0", feature = "test")]
 
-#[rustc_deprecated(
+#[deprecated(
     since = "1.0.1",
-    reason = "explanation for deprecation"
+    note = "explanation for deprecation"
 )] // invalid
 fn _deprecated_fn() {}
 ```
@@ -22,9 +22,9 @@ Example:
 #![stable(since = "1.0.0", feature = "test")]
 
 #[stable(since = "1.0.0", feature = "test")]
-#[rustc_deprecated(
+#[deprecated(
     since = "1.0.1",
-    reason = "explanation for deprecation"
+    note = "explanation for deprecation"
 )] // ok!
 fn _deprecated_fn() {}
 ```

compiler/rustc_error_codes/src/error_codes/E0550.md

@@ -1,8 +1,10 @@
+#### Note: this error code is no longer emitted by the compiler
+
 More than one `deprecated` attribute has been put on an item.
 
 Erroneous code example:
 
-```compile_fail,E0550
+```compile_fail
 #[deprecated(note = "because why not?")]
 #[deprecated(note = "right?")] // error!
 fn the_banished() {}

compiler/rustc_error_codes/src/error_codes/E0734.md

@@ -3,7 +3,6 @@ A stability attribute has been used outside of the standard library.
 Erroneous code example:
 
 ```compile_fail,E0734
-#[rustc_deprecated(since = "b", reason = "text")] // invalid
 #[stable(feature = "a", since = "b")] // invalid
 #[unstable(feature = "b", issue = "none")] // invalid
 fn foo(){}

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
-        DuplicatesOk
+        ErrorFollowing
     ),
 
     // Crate properties:
@@ -469,10 +468,10 @@ 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!(

compiler/rustc_lint_defs/src/builtin.rs

@@ -2201,13 +2201,12 @@ declare_lint! {
     /// used by user code.
     ///
     /// This lint is only enabled in the standard library. It works with the
-    /// use of `#[rustc_deprecated]` with a `since` field of a version in the
-    /// future. This allows something to be marked as deprecated in a future
-    /// version, and then this lint will ensure that the item is no longer
-    /// used in the standard library. See the [stability documentation] for
-    /// more details.
+    /// use of `#[deprecated]` with a `since` field of a version in the future.
+    /// This allows something to be marked as deprecated in a future version,
+    /// and then this lint will ensure that the item is no longer used in the
+    /// standard library. See the [stability documentation] for more details.
     ///
-    /// [stability documentation]: https://rustc-dev-guide.rust-lang.org/stability.html#rustc_deprecated
+    /// [stability documentation]: https://rustc-dev-guide.rust-lang.org/stability.html#deprecated
     pub DEPRECATED_IN_FUTURE,
     Allow,
     "detects use of items that will be deprecated in a future version",

compiler/rustc_middle/src/middle/stability.rs

@@ -118,8 +118,7 @@ pub fn deprecation_in_effect(depr: &Deprecation) -> bool {
     }
 
     if !is_since_rustc_version {
-        // The `since` field doesn't have semantic purpose in the stable `deprecated`
-        // attribute, only in `rustc_deprecated`.
+        // The `since` field doesn't have semantic purpose without `#![staged_api]`.
         return true;
     }
 
@@ -336,7 +335,7 @@ impl<'tcx> TyCtxt<'tcx> {
                 // topmost deprecation. For example, if a struct is deprecated,
                 // the use of a field won't be linted.
                 //
-                // #[rustc_deprecated] however wants to emit down the whole
+                // With #![staged_api], we want to emit down the whole
                 // hierarchy.
                 let depr_attr = &depr_entry.attr;
                 if !skip || depr_attr.is_since_rustc_version {