Remove UnknownMetaItem error

compiler/rustc_attr_parsing/messages.ftl

@@ -213,10 +213,6 @@ attr_parsing_stability_outside_std = stability attributes may not be used outsid
 attr_parsing_suffixed_literal_in_attribute = suffixed literals are not allowed in attributes
     .help = instead of using a suffixed literal (`1u8`, `1.0f32`, etc.), use an unsuffixed version (`1`, `1.0`, etc.)
 
-attr_parsing_unknown_meta_item =
-    unknown meta item '{$item}'
-    .label = expected one of {$expected}
-
 attr_parsing_unknown_version_literal =
     unknown version literal format, assuming it refers to a future version
 

compiler/rustc_attr_parsing/src/attributes/deprecation.rs

@@ -110,13 +110,12 @@ impl<S: Stage> SingleAttributeParser<S> for DeprecationParser {
                                 Some(get(cx, name, param.span(), param.args(), &suggestion)?);
                         }
                         _ => {
-                            cx.unknown_key(
+                            cx.expected_specific_argument(
                                 param.span(),
-                                param.path().to_string(),
                                 if features.deprecated_suggestion() {
-                                    &["since", "note", "suggestion"]
+                                    &[sym::since, sym::note, sym::suggestion]
                                 } else {
-                                    &["since", "note"]
+                                    &[sym::since, sym::note]
                                 },
                             );
                             return None;

compiler/rustc_attr_parsing/src/attributes/prototype.rs

@@ -46,9 +46,8 @@ impl<S: Stage> SingleAttributeParser<S> for CustomMirParser {
                 extract_value(cx, sym::dialect, arg, meta_item.span(), &mut dialect, &mut failed);
             } else if let Some(arg) = meta_item.word_is(sym::phase) {
                 extract_value(cx, sym::phase, arg, meta_item.span(), &mut phase, &mut failed);
-            } else if let Some(word) = meta_item.path().word() {
-                let word = word.to_string();
-                cx.unknown_key(meta_item.span(), word, &["dialect", "phase"]);
+            } else if let Some(..) = meta_item.path().word() {
+                cx.expected_specific_argument(meta_item.span(), &[sym::dialect, sym::phase]);
                 failed = true;
             } else {
                 cx.expected_name_value(meta_item.span(), None);

compiler/rustc_attr_parsing/src/attributes/stability.rs

@@ -315,11 +315,7 @@ pub(crate) fn parse_stability<S: Stage>(
                 insert_value_into_option_or_error(cx, &param, &mut since, word.unwrap())?
             }
             _ => {
-                cx.emit_err(session_diagnostics::UnknownMetaItem {
-                    span: param_span,
-                    item: param.path().to_string(),
-                    expected: &["feature", "since"],
-                });
+                cx.expected_specific_argument(param_span, &[sym::feature, sym::since]);
                 return None;
             }
         }
@@ -426,11 +422,17 @@ pub(crate) fn parse_unstability<S: Stage>(
                 insert_value_into_option_or_error(cx, &param, &mut old_name, word.unwrap())?
             }
             _ => {
-                cx.emit_err(session_diagnostics::UnknownMetaItem {
-                    span: param.span(),
-                    item: param.path().to_string(),
-                    expected: &["feature", "reason", "issue", "soft", "implied_by", "old_name"],
-                });
+                cx.expected_specific_argument(
+                    param.span(),
+                    &[
+                        sym::feature,
+                        sym::reason,
+                        sym::issue,
+                        sym::soft,
+                        sym::implied_by,
+                        sym::old_name,
+                    ],
+                );
                 return None;
             }
         }

compiler/rustc_attr_parsing/src/context.rs

@@ -77,7 +77,7 @@ use crate::attributes::transparency::TransparencyParser;
 use crate::attributes::{AttributeParser as _, Combine, Single, WithoutArgs};
 use crate::parser::{ArgParser, RefPathParser};
 use crate::session_diagnostics::{
-    AttributeParseError, AttributeParseErrorReason, ParsedDescription, UnknownMetaItem,
+    AttributeParseError, AttributeParseErrorReason, ParsedDescription,
 };
 use crate::target_checking::AllowedTargets;
 
@@ -425,15 +425,6 @@ impl<'f, 'sess: 'f, S: Stage> SharedContext<'f, 'sess, S> {
 }
 
 impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
-    pub(crate) fn unknown_key(
-        &self,
-        span: Span,
-        found: String,
-        options: &[&'static str],
-    ) -> ErrorGuaranteed {
-        self.emit_err(UnknownMetaItem { span, item: found, expected: options })
-    }
-
     fn emit_parse_error(
         &self,
         span: Span,

compiler/rustc_attr_parsing/src/session_diagnostics.rs

@@ -64,26 +64,6 @@ pub(crate) struct DocAttributeNotAttribute {
     pub attribute: Symbol,
 }
 
-/// Error code: E0541
-pub(crate) struct UnknownMetaItem<'a> {
-    pub span: Span,
-    pub item: String,
-    pub expected: &'a [&'a str],
-}
-
-// Manual implementation to be able to format `expected` items correctly.
-impl<'a, G: EmissionGuarantee> Diagnostic<'a, G> for UnknownMetaItem<'_> {
-    fn into_diag(self, dcx: DiagCtxtHandle<'a>, level: Level) -> Diag<'a, G> {
-        let expected = self.expected.iter().map(|name| format!("`{name}`")).collect::<Vec<_>>();
-        Diag::new(dcx, level, fluent::attr_parsing_unknown_meta_item)
-            .with_span(self.span)
-            .with_code(E0541)
-            .with_arg("item", self.item)
-            .with_arg("expected", expected.join(", "))
-            .with_span_label(self.span, fluent::attr_parsing_label)
-    }
-}
-
 #[derive(Diagnostic)]
 #[diag(attr_parsing_missing_since, code = E0542)]
 pub(crate) struct MissingSince {

compiler/rustc_error_codes/src/error_codes/E0541.md

@@ -1,8 +1,10 @@
+#### Note: this error code is no longer emitted by the compiler.
+
 An unknown meta item was used.
 
 Erroneous code example:
 
-```compile_fail,E0541
+```compile_fail (no longer emitted)
 #[deprecated(
     since="1.0.0",
     // error: unknown meta item

tests/ui/deprecation/deprecation-sanity.rs

@@ -3,7 +3,7 @@
 // Various checks that deprecation attributes are used correctly
 
 mod bogus_attribute_types_1 {
-    #[deprecated(since = "a", note = "a", reason)] //~ ERROR unknown meta item 'reason'
+    #[deprecated(since = "a", note = "a", reason)] //~ ERROR malformed `deprecated` attribute input [E0539]
     fn f1() { }
 
     #[deprecated(since = "a", note)] //~ ERROR malformed `deprecated` attribute input [E0539]

tests/ui/deprecation/deprecation-sanity.stderr

@@ -1,8 +1,10 @@
-error[E0541]: unknown meta item 'reason'
-  --> $DIR/deprecation-sanity.rs:6:43
+error[E0539]: malformed `deprecated` attribute input
+  --> $DIR/deprecation-sanity.rs:6:5
    |
 LL |     #[deprecated(since = "a", note = "a", reason)]
-   |                                           ^^^^^^ expected one of `since`, `note`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^------^^
+   |                                           |
+   |                                           valid arguments are `since` or `note`
 
 error[E0539]: malformed `deprecated` attribute input
   --> $DIR/deprecation-sanity.rs:9:5
@@ -86,5 +88,5 @@ LL | #[deprecated = "hello"]
 
 error: aborting due to 10 previous errors
 
-Some errors have detailed explanations: E0538, E0539, E0541, E0565.
+Some errors have detailed explanations: E0538, E0539, E0565.
 For more information about an error, try `rustc --explain E0538`.

tests/ui/stability-attribute/stability-attribute-sanity-2.rs

@@ -7,7 +7,7 @@
 #[stable(feature = "a", feature = "b", since = "1.0.0")] //~ ERROR malformed `stable` attribute input [E0538]
 fn f1() { }
 
-#[stable(feature = "a", sinse = "1.0.0")] //~ ERROR unknown meta item 'sinse'
+#[stable(feature = "a", sinse = "1.0.0")] //~ ERROR malformed `stable` attribute input [E0539]
 fn f2() { }
 
 #[unstable(feature = "a", issue = "no")]

tests/ui/stability-attribute/stability-attribute-sanity-2.stderr

@@ -7,11 +7,14 @@ LL | #[stable(feature = "a", feature = "b", since = "1.0.0")]
    | |                       found `feature` used as a key more than once
    | help: must be of the form: `#[stable(feature = "name", since = "version")]`
 
-error[E0541]: unknown meta item 'sinse'
-  --> $DIR/stability-attribute-sanity-2.rs:10:25
+error[E0539]: malformed `stable` attribute input
+  --> $DIR/stability-attribute-sanity-2.rs:10:1
    |
 LL | #[stable(feature = "a", sinse = "1.0.0")]
-   |                         ^^^^^^^^^^^^^^^ expected one of `feature`, `since`
+   | ^^^^^^^^^^^^^^^^^^^^^^^^---------------^^
+   | |                       |
+   | |                       valid arguments are `feature` or `since`
+   | help: must be of the form: `#[stable(feature = "name", since = "version")]`
 
 error[E0545]: `issue` must be a non-zero numeric string or "none"
   --> $DIR/stability-attribute-sanity-2.rs:13:27
@@ -23,5 +26,5 @@ LL | #[unstable(feature = "a", issue = "no")]
 
 error: aborting due to 3 previous errors
 
-Some errors have detailed explanations: E0538, E0541, E0545.
+Some errors have detailed explanations: E0538, E0539, E0545.
 For more information about an error, try `rustc --explain E0538`.

tests/ui/stability-attribute/stability-attribute-sanity.rs

@@ -5,7 +5,7 @@
 #![stable(feature = "rust1", since = "1.0.0")]
 
 mod bogus_attribute_types_1 {
-    #[stable(feature = "a", since = "4.4.4", reason)] //~ ERROR unknown meta item 'reason' [E0541]
+    #[stable(feature = "a", since = "4.4.4", reason)] //~ ERROR malformed `stable` attribute input [E0539]
     fn f1() { }
 
     #[stable(feature = "a", since)] //~ ERROR malformed `stable` attribute input [E0539]

tests/ui/stability-attribute/stability-attribute-sanity.stderr

@@ -1,8 +1,11 @@
-error[E0541]: unknown meta item 'reason'
-  --> $DIR/stability-attribute-sanity.rs:8:46
+error[E0539]: malformed `stable` attribute input
+  --> $DIR/stability-attribute-sanity.rs:8:5
    |
 LL |     #[stable(feature = "a", since = "4.4.4", reason)]
-   |                                              ^^^^^^ expected one of `feature`, `since`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^------^^
+   |     |                                        |
+   |     |                                        valid arguments are `feature` or `since`
+   |     help: must be of the form: `#[stable(feature = "name", since = "version")]`
 
 error[E0539]: malformed `stable` attribute input
   --> $DIR/stability-attribute-sanity.rs:11:5
@@ -138,5 +141,5 @@ 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, E0711.
+Some errors have detailed explanations: E0539, E0542, E0543, E0544, E0546, E0547, E0549, E0711.
 For more information about an error, try `rustc --explain E0539`.