GuillaumeGomez · Oct 30, 2026
diff --git a/compiler/rustc_attr_parsing/src/attributes/doc.rs b/compiler/rustc_attr_parsing/src/attributes/doc.rs
@@ -20,8 +20,8 @@ use crate::diagnostics::{
     DocAutoCfgHideShowUnexpectedItem, DocAutoCfgHideShowUnexpectedItemAfterValues,
     DocAutoCfgHideShowValuesMix, DocAutoCfgWrongLiteral, DocInlineConflict, DocInlineOnlyUse,
     DocKeywordNotKeyword, DocTestLiteral, DocTestTakesList, DocTestUnknown, DocUnknownAny,
-    DocUnknownInclude, DocUnknownPasses, DocUnknownPlugins, DocUnknownSpotlight, ExpectedNameValue,
-    ExpectedNoArgs, IllFormedAttributeInput, MalformedDoc, UnusedDuplicate,
+    DocUnknownInclude, DocUnknownPasses, DocUnknownPlugins, DocUnknownSpotlight, ExpectedNoArgs,
+    IllFormedAttributeInput, MalformedDoc, UnusedDuplicate,
 };
 use crate::parser::{
     ArgParser, MetaItemListParser, MetaItemOrLitParser, MetaItemParser, OwnedPathParser,
@@ -64,11 +64,6 @@ fn check_attr_not_crate_level(
     true
 }
 
-// FIXME: To be removed once merged and replace with `cx.expected_name_value(span, _name)`.
-fn expected_name_value(cx: &mut AcceptContext<'_, '_>, span: Span, _name: Option<Symbol>) {
-    cx.emit_lint(INVALID_DOC_ATTRIBUTES, ExpectedNameValue, span);
-}
-
 // FIXME: remove this method once merged and use `cx.expected_no_args(span)` instead.
 fn expected_no_args(cx: &mut AcceptContext<'_, '_>, span: Span) {
     cx.emit_lint(INVALID_DOC_ATTRIBUTES, ExpectedNoArgs, span);
@@ -92,7 +87,7 @@ fn parse_keyword_and_attribute(
     attr_name: Symbol,
 ) {
     let Some(nv) = args.as_name_value() else {
-        expected_name_value(cx, args.span().unwrap_or(path.span()), path.word_sym());
+        cx.adcx().expected_name_value(args.span().unwrap_or(path.span()), path.word_sym());
         return;
     };
 
@@ -555,7 +550,8 @@ impl DocParser {
         macro_rules! string_arg_and_crate_level {
             ($ident: ident) => {{
                 let Some(nv) = args.as_name_value() else {
-                    expected_name_value(cx, args.span().unwrap_or(path.span()), path.word_sym());
+                    cx.adcx()
+                        .expected_name_value(args.span().unwrap_or(path.span()), path.word_sym());
                     return;
                 };
 
@@ -733,7 +729,7 @@ impl DocParser {
                             self.parse_single_doc_attr_item(cx, mip);
                         }
                         MetaItemOrLitParser::Lit(lit) => {
-                            expected_name_value(cx, lit.span, None);
+                            cx.adcx().expected_name_value(lit.span, None);
                         }
                     }
                 }

diff --git a/compiler/rustc_attr_parsing/src/context.rs b/compiler/rustc_attr_parsing/src/context.rs
@@ -1045,7 +1045,11 @@ impl<'a, 'f, 'sess: 'f> AttributeDiagnosticContext<'a, 'f, 'sess> {
     /// Emit an error that a `name = value` pair was expected at this span. The symbol can be given for
     /// a nicer error message talking about the specific name that was found lacking a value.
     #[track_caller]
-    fn expected_name_value(&mut self, span: Span, name: Option<Symbol>) -> ErrorGuaranteed {
+    pub(crate) fn expected_name_value(
+        &mut self,
+        span: Span,
+        name: Option<Symbol>,
+    ) -> ErrorGuaranteed {
         self.emit_parse_error(span, AttributeParseErrorReason::ExpectedNameValue(name))
     }
 

diff --git a/compiler/rustc_attr_parsing/src/diagnostics.rs b/compiler/rustc_attr_parsing/src/diagnostics.rs
@@ -384,13 +384,6 @@ pub(crate) struct MalformedDoc;
 )]
 pub(crate) struct ExpectedNoArgs;
 
-#[derive(Diagnostic)]
-#[diag("expected this to be of the form `... = \"...\"`")]
-#[warning(
-    "this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!"
-)]
-pub(crate) struct ExpectedNameValue;
-
 #[derive(Diagnostic)]
 #[diag("malformed `{$attribute}` attribute")]
 #[help("{$options}")]

diff --git a/tests/rustdoc-ui/bad-render-options.rs b/tests/rustdoc-ui/bad-render-options.rs
@@ -1,18 +1,19 @@
 // regression test for https://github.com/rust-lang/rust/issues/149187
 #![deny(invalid_doc_attributes)]
+//~^ NOTE
 
 #![doc(html_favicon_url)]
 //~^ ERROR
-//~| WARN
+//~| NOTE expected this to be of the form
 #![doc(html_logo_url)]
 //~^ ERROR
-//~| WARN
+//~| NOTE expected this to be of the form
 #![doc(html_playground_url)]
 //~^ ERROR
-//~| WARN
+//~| NOTE expected this to be of the form
 #![doc(issue_tracker_base_url)]
 //~^ ERROR
-//~| WARN
+//~| NOTE expected this to be of the form
 #![doc(html_favicon_url = 1)]
 //~^ ERROR
 //~| WARN

diff --git a/tests/rustdoc-ui/bad-render-options.stderr b/tests/rustdoc-ui/bad-render-options.stderr
@@ -1,74 +1,74 @@
-error: expected this to be of the form `... = "..."`
-  --> $DIR/bad-render-options.rs:4:8
+error[E0539]: malformed `doc` attribute input
+  --> $DIR/bad-render-options.rs:5:4
    |
 LL | #![doc(html_favicon_url)]
-   |        ^^^^^^^^^^^^^^^^
-   |
-   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
-note: the lint level is defined here
-  --> $DIR/bad-render-options.rs:2:9
-   |
-LL | #![deny(invalid_doc_attributes)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^
+   |    ^^^^----------------^
+   |        |
+   |        expected this to be of the form `html_favicon_url = "..."`
 
-error: expected this to be of the form `... = "..."`
-  --> $DIR/bad-render-options.rs:7:8
+error[E0539]: malformed `doc` attribute input
+  --> $DIR/bad-render-options.rs:8:4
    |
 LL | #![doc(html_logo_url)]
-   |        ^^^^^^^^^^^^^
-   |
-   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   |    ^^^^-------------^
+   |        |
+   |        expected this to be of the form `html_logo_url = "..."`
 
-error: expected this to be of the form `... = "..."`
-  --> $DIR/bad-render-options.rs:10:8
+error[E0539]: malformed `doc` attribute input
+  --> $DIR/bad-render-options.rs:11:4
    |
 LL | #![doc(html_playground_url)]
-   |        ^^^^^^^^^^^^^^^^^^^
-   |
-   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   |    ^^^^-------------------^
+   |        |
+   |        expected this to be of the form `html_playground_url = "..."`
 
-error: expected this to be of the form `... = "..."`
-  --> $DIR/bad-render-options.rs:13:8
+error[E0539]: malformed `doc` attribute input
+  --> $DIR/bad-render-options.rs:14:4
    |
 LL | #![doc(issue_tracker_base_url)]
-   |        ^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   |    ^^^^----------------------^
+   |        |
+   |        expected this to be of the form `issue_tracker_base_url = "..."`
 
 error: malformed `doc` attribute input
-  --> $DIR/bad-render-options.rs:16:27
+  --> $DIR/bad-render-options.rs:17:27
    |
 LL | #![doc(html_favicon_url = 1)]
    |                           ^
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+note: the lint level is defined here
+  --> $DIR/bad-render-options.rs:2:9
+   |
+LL | #![deny(invalid_doc_attributes)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^
 
 error: malformed `doc` attribute input
-  --> $DIR/bad-render-options.rs:19:24
+  --> $DIR/bad-render-options.rs:20:24
    |
 LL | #![doc(html_logo_url = 2)]
    |                        ^
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 error: malformed `doc` attribute input
-  --> $DIR/bad-render-options.rs:22:30
+  --> $DIR/bad-render-options.rs:23:30
    |
 LL | #![doc(html_playground_url = 3)]
    |                              ^
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 error: malformed `doc` attribute input
-  --> $DIR/bad-render-options.rs:25:33
+  --> $DIR/bad-render-options.rs:26:33
    |
 LL | #![doc(issue_tracker_base_url = 4)]
    |                                 ^
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 error: didn't expect any arguments here
-  --> $DIR/bad-render-options.rs:28:23
+  --> $DIR/bad-render-options.rs:29:23
    |
 LL | #![doc(html_no_source = "asdf")]
    |                       ^^^^^^^^
@@ -77,3 +77,4 @@ LL | #![doc(html_no_source = "asdf")]
 
 error: aborting due to 9 previous errors
 
+For more information about this error, try `rustc --explain E0539`.
diff --git a/tests/rustdoc-ui/lints/doc-attr.rs b/tests/rustdoc-ui/lints/doc-attr.rs
@@ -3,10 +3,7 @@
 
 #[doc(123)]
 //~^ ERROR
-//~| WARN
 #[doc("hello", "bar")]
 //~^ ERROR
 //~| ERROR
-//~| WARN
-//~| WARN
 fn bar() {}
diff --git a/tests/rustdoc-ui/lints/doc-attr.stderr b/tests/rustdoc-ui/lints/doc-attr.stderr
@@ -1,31 +1,27 @@
-error: expected this to be of the form `... = "..."`
-  --> $DIR/doc-attr.rs:4:7
+error[E0539]: malformed `doc` attribute input
+  --> $DIR/doc-attr.rs:4:3
    |
 LL | #[doc(123)]
-   |       ^^^
-   |
-   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
-note: the lint level is defined here
-  --> $DIR/doc-attr.rs:2:9
-   |
-LL | #![deny(invalid_doc_attributes)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^
+   |   ^^^^---^
+   |       |
+   |       expected this to be of the form `... = "..."`
 
-error: expected this to be of the form `... = "..."`
-  --> $DIR/doc-attr.rs:7:7
+error[E0539]: malformed `doc` attribute input
+  --> $DIR/doc-attr.rs:6:3
    |
 LL | #[doc("hello", "bar")]
-   |       ^^^^^^^
-   |
-   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   |   ^^^^-------^^^^^^^^
+   |       |
+   |       expected this to be of the form `... = "..."`
 
-error: expected this to be of the form `... = "..."`
-  --> $DIR/doc-attr.rs:7:16
+error[E0539]: malformed `doc` attribute input
+  --> $DIR/doc-attr.rs:6:3
    |
 LL | #[doc("hello", "bar")]
-   |                ^^^^^
-   |
-   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   |   ^^^^^^^^^^^^^-----^
+   |                |
+   |                expected this to be of the form `... = "..."`
 
 error: aborting due to 3 previous errors
 
+For more information about this error, try `rustc --explain E0539`.
diff --git a/tests/rustdoc-ui/lints/invalid-doc-attr-2.rs b/tests/rustdoc-ui/lints/invalid-doc-attr-2.rs
@@ -2,6 +2,5 @@
 
 #![doc("other attribute")]
 //~^ ERROR
-//~| WARN
 #![doc]
 //~^ ERROR
diff --git a/tests/rustdoc-ui/lints/invalid-doc-attr-2.stderr b/tests/rustdoc-ui/lints/invalid-doc-attr-2.stderr
@@ -1,21 +1,23 @@
-error: expected this to be of the form `... = "..."`
-  --> $DIR/invalid-doc-attr-2.rs:3:8
+error[E0539]: malformed `doc` attribute input
+  --> $DIR/invalid-doc-attr-2.rs:3:4
    |
 LL | #![doc("other attribute")]
-   |        ^^^^^^^^^^^^^^^^^
+   |    ^^^^-----------------^
+   |        |
+   |        expected this to be of the form `... = "..."`
+
+error: valid forms for the attribute are `doc = "doc comment"`, `doc(alias)`, `doc(auto_cfg)`, `doc(cfg)`, `doc(hidden)`, `doc(html_favicon_url)`, `doc(html_logo_url)`, `doc(html_no_source)`, `doc(html_playground_url)`, `doc(html_root_url)`, `doc(inline)`, `doc(issue_tracker_base_url)`, `doc(masked)`, `doc(no_inline)`, `doc(notable_trait)`, and `doc(test)`
+  --> $DIR/invalid-doc-attr-2.rs:5:4
+   |
+LL | #![doc]
+   |    ^^^
    |
-   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 note: the lint level is defined here
   --> $DIR/invalid-doc-attr-2.rs:1:9
    |
 LL | #![deny(invalid_doc_attributes)]
    |         ^^^^^^^^^^^^^^^^^^^^^^
 
-error: valid forms for the attribute are `doc = "doc comment"`, `doc(alias)`, `doc(auto_cfg)`, `doc(cfg)`, `doc(hidden)`, `doc(html_favicon_url)`, `doc(html_logo_url)`, `doc(html_no_source)`, `doc(html_playground_url)`, `doc(html_root_url)`, `doc(inline)`, `doc(issue_tracker_base_url)`, `doc(masked)`, `doc(no_inline)`, `doc(notable_trait)`, and `doc(test)`
-  --> $DIR/invalid-doc-attr-2.rs:6:4
-   |
-LL | #![doc]
-   |    ^^^
-
 error: aborting due to 2 previous errors
 
+For more information about this error, try `rustc --explain E0539`.