Add more docs to templates for attrs with incorrect arguments

compiler/rustc_attr_parsing/src/attributes/cfg.rs

@@ -16,7 +16,10 @@ use crate::{
     CfgMatchesLintEmitter, fluent_generated, parse_version, session_diagnostics, try_gate_cfg,
 };
 
-pub const CFG_TEMPLATE: AttributeTemplate = template!(List: &["predicate"]);
+pub const CFG_TEMPLATE: AttributeTemplate = template!(
+    List: &["predicate"],
+    "https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg-attribute"
+);
 
 pub fn parse_cfg_attr<'c, S: Stage>(
     cx: &'c mut AcceptContext<'_, '_, S>,

compiler/rustc_attr_parsing/src/attributes/inline.rs

@@ -18,7 +18,11 @@ impl<S: Stage> SingleAttributeParser<S> for InlineParser {
     const PATH: &'static [Symbol] = &[sym::inline];
     const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepOutermost;
     const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::WarnButFutureError;
-    const TEMPLATE: AttributeTemplate = template!(Word, List: &["always", "never"]);
+    const TEMPLATE: AttributeTemplate = template!(
+        Word,
+        List: &["always", "never"],
+        "https://doc.rust-lang.org/reference/attributes/codegen.html#the-inline-attribute"
+    );
 
     fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
         match args {

compiler/rustc_attr_parsing/src/attributes/link_attrs.rs

@@ -16,7 +16,10 @@ impl<S: Stage> SingleAttributeParser<S> for LinkNameParser {
     const PATH: &[Symbol] = &[sym::link_name];
     const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepInnermost;
     const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::WarnButFutureError;
-    const TEMPLATE: AttributeTemplate = template!(NameValueStr: "name");
+    const TEMPLATE: AttributeTemplate = template!(
+        NameValueStr: "name",
+        "https://doc.rust-lang.org/reference/items/external-blocks.html#the-link_name-attribute"
+    );
 
     fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
         let Some(nv) = args.name_value() else {
@@ -38,7 +41,10 @@ impl<S: Stage> SingleAttributeParser<S> for LinkSectionParser {
     const PATH: &[Symbol] = &[sym::link_section];
     const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepInnermost;
     const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::WarnButFutureError;
-    const TEMPLATE: AttributeTemplate = template!(NameValueStr: "name");
+    const TEMPLATE: AttributeTemplate = template!(
+        NameValueStr: "name",
+        "https://doc.rust-lang.org/reference/abi.html#the-link_section-attribute"
+    );
 
     fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
         let Some(nv) = args.name_value() else {
@@ -94,7 +100,10 @@ impl<S: Stage> SingleAttributeParser<S> for LinkOrdinalParser {
     const PATH: &[Symbol] = &[sym::link_ordinal];
     const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepOutermost;
     const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
-    const TEMPLATE: AttributeTemplate = template!(List: &["ordinal"]);
+    const TEMPLATE: AttributeTemplate = template!(
+        List: &["ordinal"],
+        "https://doc.rust-lang.org/reference/items/external-blocks.html#the-link_ordinal-attribute"
+    );
 
     fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
         let ordinal = parse_single_integer(cx, args)?;

compiler/rustc_attr_parsing/src/attributes/macro_attrs.rs

@@ -31,7 +31,10 @@ pub(crate) struct MacroUseParser {
     first_span: Option<Span>,
 }
 
-const MACRO_USE_TEMPLATE: AttributeTemplate = template!(Word, List: &["name1, name2, ..."]);
+const MACRO_USE_TEMPLATE: AttributeTemplate = template!(
+    Word, List: &["name1, name2, ..."],
+    "https://doc.rust-lang.org/reference/macros-by-example.html#the-macro_use-attribute"
+);
 
 impl<S: Stage> AttributeParser<S> for MacroUseParser {
     const ATTRIBUTES: AcceptMapping<Self, S> = &[(

compiler/rustc_attr_parsing/src/attributes/must_use.rs

@@ -14,7 +14,10 @@ impl<S: Stage> SingleAttributeParser<S> for MustUseParser {
     const PATH: &[Symbol] = &[sym::must_use];
     const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepOutermost;
     const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::WarnButFutureError;
-    const TEMPLATE: AttributeTemplate = template!(Word, NameValueStr: "reason");
+    const TEMPLATE: AttributeTemplate = template!(
+        Word, NameValueStr: "reason",
+        "https://doc.rust-lang.org/reference/attributes/diagnostics.html#the-must_use-attribute"
+    );
 
     fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
         Some(AttributeKind::MustUse {

compiler/rustc_attr_parsing/src/attributes/path.rs

@@ -12,7 +12,10 @@ impl<S: Stage> SingleAttributeParser<S> for PathParser {
     const PATH: &[Symbol] = &[sym::path];
     const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepOutermost;
     const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::WarnButFutureError;
-    const TEMPLATE: AttributeTemplate = template!(NameValueStr: "file");
+    const TEMPLATE: AttributeTemplate = template!(
+        NameValueStr: "file",
+        "https://doc.rust-lang.org/reference/items/modules.html#the-path-attribute"
+    );
 
     fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
         let Some(nv) = args.name_value() else {

compiler/rustc_attr_parsing/src/attributes/proc_macro_attrs.rs

@@ -28,8 +28,10 @@ impl<S: Stage> SingleAttributeParser<S> for ProcMacroDeriveParser {
     const PATH: &[Symbol] = &[sym::proc_macro_derive];
     const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepOutermost;
     const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
-    const TEMPLATE: AttributeTemplate =
+    const TEMPLATE: AttributeTemplate = template!(
-        template!(List: &["TraitName", "TraitName, attributes(name1, name2, ...)"]);
+        List: &["TraitName", "TraitName, attributes(name1, name2, ...)"],
+        "https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros"
+    );
 
     fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
         let (trait_name, helper_attrs) = parse_derive_like(cx, args, true)?;

compiler/rustc_attr_parsing/src/attributes/repr.rs

@@ -26,7 +26,10 @@ impl<S: Stage> CombineAttributeParser<S> for ReprParser {
     const CONVERT: ConvertFn<Self::Item> =
         |items, first_span| AttributeKind::Repr { reprs: items, first_span };
     // FIXME(jdonszelmann): never used
-    const TEMPLATE: AttributeTemplate = template!(List: &["C", "Rust", "transparent", "align(...)", "packed(...)", "<integer type>"]);
+    const TEMPLATE: AttributeTemplate = template!(
+        List: &["C", "Rust", "transparent", "align(...)", "packed(...)", "<integer type>"],
+        "https://doc.rust-lang.org/reference/type-layout.html#representations"
+    );
 
     fn extend<'c>(
         cx: &'c mut AcceptContext<'_, '_, S>,

compiler/rustc_attr_parsing/src/attributes/test_attrs.rs

@@ -13,7 +13,10 @@ impl<S: Stage> SingleAttributeParser<S> for IgnoreParser {
     const PATH: &[Symbol] = &[sym::ignore];
     const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepOutermost;
     const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Warn;
-    const TEMPLATE: AttributeTemplate = template!(Word, NameValueStr: "reason");
+    const TEMPLATE: AttributeTemplate = template!(
+        Word, NameValueStr: "reason",
+        "https://doc.rust-lang.org/reference/attributes/testing.html#the-ignore-attribute"
+    );
 
     fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
         Some(AttributeKind::Ignore {
@@ -51,8 +54,10 @@ impl<S: Stage> SingleAttributeParser<S> for ShouldPanicParser {
     const PATH: &[Symbol] = &[sym::should_panic];
     const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepOutermost;
     const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::WarnButFutureError;
-    const TEMPLATE: AttributeTemplate =
+    const TEMPLATE: AttributeTemplate = template!(
-        template!(Word, List: &[r#"expected = "reason""#], NameValueStr: "reason");
+        Word, List: &[r#"expected = "reason""#], NameValueStr: "reason",
+        "https://doc.rust-lang.org/reference/attributes/testing.html#the-should_panic-attribute"
+    );
 
     fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
         Some(AttributeKind::ShouldPanic {

compiler/rustc_attr_parsing/src/session_diagnostics.rs

@@ -691,6 +691,9 @@ impl<'a, G: EmissionGuarantee> Diagnostic<'a, G> for AttributeParseError {
             }
         }
 
+        if let Some(link) = self.template.docs {
+            diag.note(format!("for more information, visit <{link}>"));
+        }
         let suggestions = self.template.suggestions(false, &name);
         diag.span_suggestions(
             self.attr_span,

compiler/rustc_feature/src/builtin_attrs.rs

@@ -609,7 +609,10 @@ pub static BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
     ),
     ungated!(
         repr, Normal,
-        template!(List: &["C"], "https://doc.rust-lang.org/reference/type-layout.html#representations"),
+        template!(
+            List: &["C", "Rust", "transparent", "align(...)", "packed(...)", "<integer type>"],
+            "https://doc.rust-lang.org/reference/type-layout.html#representations"
+        ),
         DuplicatesOk, EncodeCrossCrate::No
     ),
     // FIXME(#82232, #143834): temporarily renamed to mitigate `#[align]` nameres ambiguity

tests/ui/attributes/invalid-macro-use.rs

@@ -8,21 +8,25 @@ extern crate std as s1;
 #[macro_use(5)]
 //~^ ERROR malformed `macro_use` attribute input
 //~| NOTE expected a valid identifier here
+//~| NOTE for more information, visit
 extern crate std as s2;
 
 #[macro_use(a = "b")]
 //~^ ERROR malformed `macro_use` attribute input
 //~| NOTE didn't expect any arguments here
+//~| NOTE for more information, visit
 extern crate std as s3;
 
 #[macro_use(a(b))]
 //~^ ERROR malformed `macro_use` attribute input
 //~| NOTE didn't expect any arguments here
+//~| NOTE for more information, visit
 extern crate std as s4;
 
 #[macro_use(a::b)]
 //~^ ERROR malformed `macro_use` attribute input
 //~| NOTE expected a valid identifier here
+//~| NOTE for more information, visit
 extern crate std as s5;
 
 #[macro_use(a)]

tests/ui/attributes/invalid-macro-use.stderr

@@ -1,11 +1,11 @@
 error[E0469]: imported macro not found
-  --> $DIR/invalid-macro-use.rs:47:13
+  --> $DIR/invalid-macro-use.rs:51:13
    |
 LL | #[macro_use(a)]
    |             ^
 
 error[E0469]: imported macro not found
-  --> $DIR/invalid-macro-use.rs:49:13
+  --> $DIR/invalid-macro-use.rs:53:13
    |
 LL | #[macro_use(b)]
    |             ^
@@ -24,6 +24,7 @@ LL | #[macro_use(5)]
    |             |
    |             expected a valid identifier here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/macros-by-example.html#the-macro_use-attribute>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[macro_use(5)]
@@ -34,13 +35,14 @@ LL + #[macro_use]
    |
 
 error[E0565]: malformed `macro_use` attribute input
-  --> $DIR/invalid-macro-use.rs:13:1
+  --> $DIR/invalid-macro-use.rs:14:1
    |
 LL | #[macro_use(a = "b")]
    | ^^^^^^^^^^^^^^-----^^
    |               |
    |               didn't expect any arguments here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/macros-by-example.html#the-macro_use-attribute>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[macro_use(a = "b")]
@@ -51,13 +53,14 @@ LL + #[macro_use]
    |
 
 error[E0565]: malformed `macro_use` attribute input
-  --> $DIR/invalid-macro-use.rs:18:1
+  --> $DIR/invalid-macro-use.rs:20:1
    |
 LL | #[macro_use(a(b))]
    | ^^^^^^^^^^^^^---^^
    |              |
    |              didn't expect any arguments here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/macros-by-example.html#the-macro_use-attribute>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[macro_use(a(b))]
@@ -68,13 +71,14 @@ LL + #[macro_use]
    |
 
 error[E0539]: malformed `macro_use` attribute input
-  --> $DIR/invalid-macro-use.rs:23:1
+  --> $DIR/invalid-macro-use.rs:26:1
    |
 LL | #[macro_use(a::b)]
    | ^^^^^^^^^^^^----^^
    |             |
    |             expected a valid identifier here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/macros-by-example.html#the-macro_use-attribute>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[macro_use(a::b)]
@@ -85,13 +89,13 @@ LL + #[macro_use]
    |
 
 error: unused attribute
-  --> $DIR/invalid-macro-use.rs:28:1
+  --> $DIR/invalid-macro-use.rs:32:1
    |
 LL | #[macro_use(a)]
    | ^^^^^^^^^^^^^^^ help: remove this attribute
    |
 note: attribute also specified here
-  --> $DIR/invalid-macro-use.rs:30:1
+  --> $DIR/invalid-macro-use.rs:34:1
    |
 LL | #[macro_use]
    | ^^^^^^^^^^^^
@@ -102,25 +106,25 @@ LL | #![deny(unused_attributes)]
    |         ^^^^^^^^^^^^^^^^^
 
 error: unused attribute
-  --> $DIR/invalid-macro-use.rs:36:1
+  --> $DIR/invalid-macro-use.rs:40:1
    |
 LL | #[macro_use(a)]
    | ^^^^^^^^^^^^^^^ help: remove this attribute
    |
 note: attribute also specified here
-  --> $DIR/invalid-macro-use.rs:34:1
+  --> $DIR/invalid-macro-use.rs:38:1
    |
 LL | #[macro_use]
    | ^^^^^^^^^^^^
 
 error: unused attribute
-  --> $DIR/invalid-macro-use.rs:42:1
+  --> $DIR/invalid-macro-use.rs:46:1
    |
 LL | #[macro_use]
    | ^^^^^^^^^^^^ help: remove this attribute
    |
 note: attribute also specified here
-  --> $DIR/invalid-macro-use.rs:40:1
+  --> $DIR/invalid-macro-use.rs:44:1
    |
 LL | #[macro_use]
    | ^^^^^^^^^^^^

tests/ui/attributes/malformed-attrs.stderr

@@ -6,6 +6,8 @@ LL | #[cfg]
    | |
    | expected this to be a list
    | help: must be of the form: `#[cfg(predicate)]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg-attribute>
 
 error: malformed `cfg_attr` attribute input
   --> $DIR/malformed-attrs.rs:101:1
@@ -354,7 +356,16 @@ error[E0539]: malformed `rustc_macro_transparency` attribute input
   --> $DIR/malformed-attrs.rs:43:1
    |
 LL | #[rustc_macro_transparency]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[rustc_macro_transparency = "transparent|semitransparent|opaque"]`
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: try changing it to one of the following valid forms of the attribute
+   |
+LL | #[rustc_macro_transparency = "opaque"]
+   |                            ++++++++++
+LL | #[rustc_macro_transparency = "semitransparent"]
+   |                            +++++++++++++++++++
+LL | #[rustc_macro_transparency = "transparent"]
+   |                            +++++++++++++++
 
 error[E0539]: malformed `repr` attribute input
   --> $DIR/malformed-attrs.rs:45:1
@@ -362,6 +373,7 @@ error[E0539]: malformed `repr` attribute input
 LL | #[repr]
    | ^^^^^^^ expected this to be a list
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/type-layout.html#representations>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL | #[repr(<integer type>)]
@@ -496,12 +508,16 @@ error[E0539]: malformed `link_name` attribute input
    |
 LL | #[link_name]
    | ^^^^^^^^^^^^ help: must be of the form: `#[link_name = "name"]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/items/external-blocks.html#the-link_name-attribute>
 
 error[E0539]: malformed `link_section` attribute input
   --> $DIR/malformed-attrs.rs:85:1
    |
 LL | #[link_section]
    | ^^^^^^^^^^^^^^^ help: must be of the form: `#[link_section = "name"]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/abi.html#the-link_section-attribute>
 
 error[E0539]: malformed `coverage` attribute input
   --> $DIR/malformed-attrs.rs:87:1
@@ -560,6 +576,7 @@ LL | #[must_use = 1]
    |              |
    |              expected a string literal here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/attributes/diagnostics.html#the-must_use-attribute>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[must_use = 1]
@@ -575,6 +592,7 @@ error[E0539]: malformed `proc_macro_derive` attribute input
 LL | #[proc_macro_derive]
    | ^^^^^^^^^^^^^^^^^^^^ expected this to be a list
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL | #[proc_macro_derive(TraitName)]
@@ -635,6 +653,8 @@ LL |     #[link_ordinal]
    |     |
    |     expected this to be a list
    |     help: must be of the form: `#[link_ordinal(ordinal)]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/items/external-blocks.html#the-link_ordinal-attribute>
 
 error[E0565]: malformed `ffi_const` attribute input
   --> $DIR/malformed-attrs.rs:168:5

tests/ui/attributes/malformed-reprs.stderr

@@ -4,6 +4,7 @@ error[E0539]: malformed `repr` attribute input
 LL | #![repr]
    | ^^^^^^^^ expected this to be a list
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/type-layout.html#representations>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #![repr]

tests/ui/attributes/unsafe/proc-unsafe-attributes.stderr

@@ -122,6 +122,7 @@ LL | #[proc_macro_derive(unsafe(Foo))]
    |                           |
    |                           didn't expect any arguments here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[proc_macro_derive(unsafe(Foo))]

tests/ui/cfg/cfg-target-compact-errors.stderr

@@ -6,6 +6,8 @@ LL | #[cfg(target(o::o))]
    | |            |
    | |            expected this to be of the form `... = "..."`
    | help: must be of the form: `#[cfg(predicate)]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg-attribute>
 
 error[E0539]: malformed `cfg` attribute input
   --> $DIR/cfg-target-compact-errors.rs:9:1
@@ -15,6 +17,8 @@ LL | #[cfg(target(os = 8))]
    | |                 |
    | |                 expected a string literal here
    | help: must be of the form: `#[cfg(predicate)]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg-attribute>
 
 error[E0539]: malformed `cfg` attribute input
   --> $DIR/cfg-target-compact-errors.rs:13:1
@@ -24,6 +28,8 @@ LL | #[cfg(target(os = "linux", pointer(width = "64")))]
    | |                          |
    | |                          expected this to be of the form `... = "..."`
    | help: must be of the form: `#[cfg(predicate)]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg-attribute>
 
 error[E0539]: malformed `cfg` attribute input
   --> $DIR/cfg-target-compact-errors.rs:17:1
@@ -33,6 +39,8 @@ LL | #[cfg(target(true))]
    | |            |
    | |            expected this to be of the form `... = "..."`
    | help: must be of the form: `#[cfg(predicate)]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg-attribute>
 
 error: `cfg` predicate key must be an identifier
   --> $DIR/cfg-target-compact-errors.rs:21:14

tests/ui/conditional-compilation/cfg-attr-syntax-validation.rs

@@ -1,21 +1,25 @@
 #[cfg]
 //~^ ERROR malformed `cfg` attribute
 //~| NOTE expected this to be a list
+//~| NOTE for more information, visit
 struct S1;
 
 #[cfg = 10]
 //~^ ERROR malformed `cfg` attribute
 //~| NOTE expected this to be a list
+//~| NOTE for more information, visit
 struct S2;
 
 #[cfg()]
 //~^ ERROR malformed `cfg` attribute
 //~| NOTE expected a single argument here
+//~| NOTE for more information, visit
 struct S3;
 
 #[cfg(a, b)]
 //~^ ERROR malformed `cfg` attribute
 //~| NOTE expected a single argument here
+//~| NOTE for more information, visit
 struct S4;
 
 #[cfg("str")] //~ ERROR `cfg` predicate key must be an identifier
@@ -29,6 +33,7 @@ struct S7;
 
 #[cfg(a = 10)] //~ ERROR malformed `cfg` attribute input
 //~^ NOTE expected a string literal here
+//~| NOTE for more information, visit
 struct S8;
 
 #[cfg(a = b"hi")]  //~ ERROR malformed `cfg` attribute input

tests/ui/conditional-compilation/cfg-attr-syntax-validation.stderr

@@ -6,63 +6,73 @@ LL | #[cfg]
    | |
    | expected this to be a list
    | help: must be of the form: `#[cfg(predicate)]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg-attribute>
 
 error[E0539]: malformed `cfg` attribute input
-  --> $DIR/cfg-attr-syntax-validation.rs:6:1
+  --> $DIR/cfg-attr-syntax-validation.rs:7:1
    |
 LL | #[cfg = 10]
    | ^^^^^^^^^^^
    | |
    | expected this to be a list
    | help: must be of the form: `#[cfg(predicate)]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg-attribute>
 
 error[E0805]: malformed `cfg` attribute input
-  --> $DIR/cfg-attr-syntax-validation.rs:11:1
+  --> $DIR/cfg-attr-syntax-validation.rs:13:1
    |
 LL | #[cfg()]
    | ^^^^^--^
    | |    |
    | |    expected a single argument here
    | help: must be of the form: `#[cfg(predicate)]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg-attribute>
 
 error[E0805]: malformed `cfg` attribute input
-  --> $DIR/cfg-attr-syntax-validation.rs:16:1
+  --> $DIR/cfg-attr-syntax-validation.rs:19:1
    |
 LL | #[cfg(a, b)]
    | ^^^^^------^
    | |    |
    | |    expected a single argument here
    | help: must be of the form: `#[cfg(predicate)]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg-attribute>
 
 error: `cfg` predicate key must be an identifier
-  --> $DIR/cfg-attr-syntax-validation.rs:21:7
+  --> $DIR/cfg-attr-syntax-validation.rs:25:7
    |
 LL | #[cfg("str")]
    |       ^^^^^
 
 error: `cfg` predicate key must be an identifier
-  --> $DIR/cfg-attr-syntax-validation.rs:24:7
+  --> $DIR/cfg-attr-syntax-validation.rs:28:7
    |
 LL | #[cfg(a::b)]
    |       ^^^^
 
 error[E0537]: invalid predicate `a`
-  --> $DIR/cfg-attr-syntax-validation.rs:27:7
+  --> $DIR/cfg-attr-syntax-validation.rs:31:7
    |
 LL | #[cfg(a())]
    |       ^^^
 
 error[E0539]: malformed `cfg` attribute input
-  --> $DIR/cfg-attr-syntax-validation.rs:30:1
+  --> $DIR/cfg-attr-syntax-validation.rs:34:1
    |
 LL | #[cfg(a = 10)]
    | ^^^^^^^^^^--^^
    | |         |
    | |         expected a string literal here
    | help: must be of the form: `#[cfg(predicate)]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg-attribute>
 
 error[E0539]: malformed `cfg` attribute input
-  --> $DIR/cfg-attr-syntax-validation.rs:34:1
+  --> $DIR/cfg-attr-syntax-validation.rs:39:1
    |
 LL | #[cfg(a = b"hi")]
    | ^^^^^^^^^^-^^^^^^
@@ -72,7 +82,7 @@ LL | #[cfg(a = b"hi")]
    = note: expected a normal string literal, not a byte string literal
 
 error: expected unsuffixed literal, found `expr` metavariable
-  --> $DIR/cfg-attr-syntax-validation.rs:40:25
+  --> $DIR/cfg-attr-syntax-validation.rs:45:25
    |
 LL |         #[cfg(feature = $expr)]
    |                         ^^^^^

tests/ui/error-codes/E0540.stderr

@@ -6,6 +6,7 @@ LL | #[inline()]
    |         |
    |         expected a single argument here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/attributes/codegen.html#the-inline-attribute>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL | #[inline(always)]

tests/ui/extern/issue-47725.rs

@@ -17,6 +17,7 @@ extern "C" {
 #[link_name]
 //~^ ERROR malformed `link_name` attribute input
 //~| HELP must be of the form
+//~| NOTE for more information, visit
 extern "C" {
     fn bar() -> u32;
 }

tests/ui/extern/issue-47725.stderr

@@ -3,6 +3,8 @@ error[E0539]: malformed `link_name` attribute input
    |
 LL | #[link_name]
    | ^^^^^^^^^^^^ help: must be of the form: `#[link_name = "name"]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/items/external-blocks.html#the-link_name-attribute>
 
 warning: attribute should be applied to a foreign function or static
   --> $DIR/issue-47725.rs:3:1

tests/ui/invalid/invalid-inline.stderr

@@ -6,6 +6,7 @@ LL | #[inline(please,no)]
    |         |
    |         expected a single argument here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/attributes/codegen.html#the-inline-attribute>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[inline(please,no)]
@@ -26,6 +27,7 @@ LL | #[inline()]
    |         |
    |         expected a single argument here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/attributes/codegen.html#the-inline-attribute>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL | #[inline(always)]

tests/ui/issues/issue-43988.stderr

@@ -6,6 +6,7 @@ LL |     #[inline(XYZ)]
    |              |
    |              valid arguments are `always` or `never`
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/attributes/codegen.html#the-inline-attribute>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL -     #[inline(XYZ)]
@@ -42,6 +43,7 @@ error[E0539]: malformed `repr` attribute input
 LL |     #[repr]
    |     ^^^^^^^ expected this to be a list
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/type-layout.html#representations>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL |     #[repr(<integer type>)]
@@ -62,6 +64,7 @@ LL |     #[inline(ABC)]
    |              |
    |              valid arguments are `always` or `never`
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/attributes/codegen.html#the-inline-attribute>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL -     #[inline(ABC)]
@@ -80,6 +83,7 @@ error[E0539]: malformed `repr` attribute input
 LL |     let _z = #[repr] 1;
    |              ^^^^^^^ expected this to be a list
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/type-layout.html#representations>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL |     let _z = #[repr(<integer type>)] 1;

tests/ui/linkage-attr/raw-dylib/windows/link-ordinal-invalid-format.stderr

@@ -6,6 +6,8 @@ LL |     #[link_ordinal("JustMonika")]
    |     |              |
    |     |              expected an integer literal here
    |     help: must be of the form: `#[link_ordinal(ordinal)]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/items/external-blocks.html#the-link_ordinal-attribute>
 
 error[E0539]: malformed `link_ordinal` attribute input
   --> $DIR/link-ordinal-invalid-format.rs:6:5
@@ -15,6 +17,8 @@ LL |     #[link_ordinal("JustMonika")]
    |     |              |
    |     |              expected an integer literal here
    |     help: must be of the form: `#[link_ordinal(ordinal)]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/items/external-blocks.html#the-link_ordinal-attribute>
 
 error: aborting due to 2 previous errors
 

tests/ui/linkage-attr/raw-dylib/windows/link-ordinal-missing-argument.rs

@@ -3,10 +3,12 @@ extern "C" {
     #[link_ordinal()]
     //~^ ERROR malformed `link_ordinal` attribute input
     //~| NOTE  expected a single argument
+    //~| NOTE for more information, visit
     fn foo();
     #[link_ordinal()]
     //~^ ERROR malformed `link_ordinal` attribute input
     //~| NOTE  expected a single argument
+    //~| NOTE for more information, visit
     static mut imported_variable: i32;
 }
 

tests/ui/linkage-attr/raw-dylib/windows/link-ordinal-missing-argument.stderr

@@ -6,15 +6,19 @@ LL |     #[link_ordinal()]
    |     |             |
    |     |             expected a single argument here
    |     help: must be of the form: `#[link_ordinal(ordinal)]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/items/external-blocks.html#the-link_ordinal-attribute>
 
 error[E0805]: malformed `link_ordinal` attribute input
-  --> $DIR/link-ordinal-missing-argument.rs:7:5
+  --> $DIR/link-ordinal-missing-argument.rs:8:5
    |
 LL |     #[link_ordinal()]
    |     ^^^^^^^^^^^^^^--^
    |     |             |
    |     |             expected a single argument here
    |     help: must be of the form: `#[link_ordinal(ordinal)]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/items/external-blocks.html#the-link_ordinal-attribute>
 
 error: aborting due to 2 previous errors
 

tests/ui/linkage-attr/raw-dylib/windows/link-ordinal-too-many-arguments.rs

@@ -3,10 +3,12 @@ extern "C" {
     #[link_ordinal(3, 4)]
     //~^ ERROR malformed `link_ordinal` attribute input
     //~| NOTE  expected a single argument
+    //~| NOTE for more information, visit
     fn foo();
     #[link_ordinal(3, 4)]
     //~^ ERROR malformed `link_ordinal` attribute input
     //~| NOTE  expected a single argument
+    //~| NOTE for more information, visit
     static mut imported_variable: i32;
 }
 

tests/ui/linkage-attr/raw-dylib/windows/link-ordinal-too-many-arguments.stderr

@@ -6,15 +6,19 @@ LL |     #[link_ordinal(3, 4)]
    |     |             |
    |     |             expected a single argument here
    |     help: must be of the form: `#[link_ordinal(ordinal)]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/items/external-blocks.html#the-link_ordinal-attribute>
 
 error[E0805]: malformed `link_ordinal` attribute input
-  --> $DIR/link-ordinal-too-many-arguments.rs:7:5
+  --> $DIR/link-ordinal-too-many-arguments.rs:8:5
    |
 LL |     #[link_ordinal(3, 4)]
    |     ^^^^^^^^^^^^^^------^
    |     |             |
    |     |             expected a single argument here
    |     help: must be of the form: `#[link_ordinal(ordinal)]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/items/external-blocks.html#the-link_ordinal-attribute>
 
 error: aborting due to 2 previous errors
 

tests/ui/macros/macro-use-bad-args-1.stderr

@@ -6,6 +6,7 @@ LL | #[macro_use(foo(bar))]
    |                |
    |                didn't expect any arguments here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/macros-by-example.html#the-macro_use-attribute>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[macro_use(foo(bar))]

tests/ui/macros/macro-use-bad-args-2.stderr

@@ -6,6 +6,7 @@ LL | #[macro_use(foo="bar")]
    |                |
    |                didn't expect any arguments here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/macros-by-example.html#the-macro_use-attribute>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[macro_use(foo="bar")]

tests/ui/parser/bad-lit-suffixes.stderr

@@ -158,6 +158,7 @@ LL | #[must_use = "string"suffix]
    |              |
    |              expected a string literal here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/attributes/diagnostics.html#the-must_use-attribute>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[must_use = "string"suffix]

tests/ui/proc-macro/attribute.rs

@@ -9,46 +9,55 @@ use proc_macro::*;
 #[proc_macro_derive]
 //~^ ERROR malformed `proc_macro_derive` attribute
 //~| NOTE expected this to be a list
+//~| NOTE for more information, visit
 pub fn foo1(input: TokenStream) -> TokenStream { input }
 
 #[proc_macro_derive = ""]
 //~^ ERROR malformed `proc_macro_derive` attribute
 //~| NOTE expected this to be a list
+//~| NOTE for more information, visit
 pub fn foo2(input: TokenStream) -> TokenStream { input }
 
 #[proc_macro_derive(d3, a, b)]
 //~^ ERROR malformed `proc_macro_derive` attribute
 //~| NOTE the only valid argument here is `attributes`
+//~| NOTE for more information, visit
 pub fn foo3(input: TokenStream) -> TokenStream { input }
 
 #[proc_macro_derive(d4, attributes(a), b)]
 //~^ ERROR malformed `proc_macro_derive` attribute
 //~| NOTE didn't expect any arguments here
+//~| NOTE for more information, visit
 pub fn foo4(input: TokenStream) -> TokenStream { input }
 
 #[proc_macro_derive("a")]
 //~^ ERROR malformed `proc_macro_derive` attribute
 //~| NOTE didn't expect a literal here
+//~| NOTE for more information, visit
 pub fn foo5(input: TokenStream) -> TokenStream { input }
 
 #[proc_macro_derive(d6 = "")]
 //~^ ERROR malformed `proc_macro_derive` attribute
 //~| NOTE didn't expect any arguments here
+//~| NOTE for more information, visit
 pub fn foo6(input: TokenStream) -> TokenStream { input }
 
 #[proc_macro_derive(m::d7)]
 //~^ ERROR malformed `proc_macro_derive` attribute
 //~| NOTE expected a valid identifier here
+//~| NOTE for more information, visit
 pub fn foo7(input: TokenStream) -> TokenStream { input }
 
 #[proc_macro_derive(d8(a))]
 //~^ ERROR malformed `proc_macro_derive` attribute
 //~| NOTE didn't expect any arguments here
+//~| NOTE for more information, visit
 pub fn foo8(input: TokenStream) -> TokenStream { input }
 
 #[proc_macro_derive(self)]
 //~^ ERROR malformed `proc_macro_derive` attribute
 //~| NOTE expected a valid identifier here
+//~| NOTE for more information, visit
 pub fn foo9(input: TokenStream) -> TokenStream { input }
 
 #[proc_macro_derive(PartialEq)] // OK
@@ -57,34 +66,41 @@ pub fn foo10(input: TokenStream) -> TokenStream { input }
 #[proc_macro_derive(d11, a)]
 //~^ ERROR malformed `proc_macro_derive` attribute
 //~| NOTE the only valid argument here is `attributes`
+//~| NOTE for more information, visit
 pub fn foo11(input: TokenStream) -> TokenStream { input }
 
 #[proc_macro_derive(d12, attributes)]
 //~^ ERROR malformed `proc_macro_derive` attribute
 //~| NOTE expected this to be a list
+//~| NOTE for more information, visit
 pub fn foo12(input: TokenStream) -> TokenStream { input }
 
 #[proc_macro_derive(d13, attributes("a"))]
 //~^ ERROR malformed `proc_macro_derive` attribute
 //~| NOTE expected a valid identifier here
+//~| NOTE for more information, visit
 pub fn foo13(input: TokenStream) -> TokenStream { input }
 
 #[proc_macro_derive(d14, attributes(a = ""))]
 //~^ ERROR malformed `proc_macro_derive` attribute
 //~| NOTE didn't expect any arguments here
+//~| NOTE for more information, visit
 pub fn foo14(input: TokenStream) -> TokenStream { input }
 
 #[proc_macro_derive(d15, attributes(m::a))]
 //~^ ERROR malformed `proc_macro_derive` attribute
 //~| NOTE expected a valid identifier here
+//~| NOTE for more information, visit
 pub fn foo15(input: TokenStream) -> TokenStream { input }
 
 #[proc_macro_derive(d16, attributes(a(b)))]
 //~^ ERROR malformed `proc_macro_derive` attribute
 //~| NOTE didn't expect any arguments here
+//~| NOTE for more information, visit
 pub fn foo16(input: TokenStream) -> TokenStream { input }
 
 #[proc_macro_derive(d17, attributes(self))]
 //~^ ERROR malformed `proc_macro_derive` attribute
 //~| NOTE expected a valid identifier here
+//~| NOTE for more information, visit
 pub fn foo17(input: TokenStream) -> TokenStream { input }

tests/ui/proc-macro/attribute.stderr

@@ -4,6 +4,7 @@ error[E0539]: malformed `proc_macro_derive` attribute input
 LL | #[proc_macro_derive]
    | ^^^^^^^^^^^^^^^^^^^^ expected this to be a list
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL | #[proc_macro_derive(TraitName)]
@@ -12,11 +13,12 @@ LL | #[proc_macro_derive(TraitName, attributes(name1, name2, ...))]
    |                    ++++++++++++++++++++++++++++++++++++++++++
 
 error[E0539]: malformed `proc_macro_derive` attribute input
-  --> $DIR/attribute.rs:14:1
+  --> $DIR/attribute.rs:15:1
    |
 LL | #[proc_macro_derive = ""]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^ expected this to be a list
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[proc_macro_derive = ""]
@@ -27,13 +29,14 @@ LL + #[proc_macro_derive(TraitName, attributes(name1, name2, ...))]
    |
 
 error[E0539]: malformed `proc_macro_derive` attribute input
-  --> $DIR/attribute.rs:19:1
+  --> $DIR/attribute.rs:21:1
    |
 LL | #[proc_macro_derive(d3, a, b)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^-^^^^^
    |                         |
    |                         the only valid argument here is `attributes`
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[proc_macro_derive(d3, a, b)]
@@ -44,13 +47,14 @@ LL + #[proc_macro_derive(TraitName, attributes(name1, name2, ...))]
    |
 
 error[E0565]: malformed `proc_macro_derive` attribute input
-  --> $DIR/attribute.rs:24:1
+  --> $DIR/attribute.rs:27:1
    |
 LL | #[proc_macro_derive(d4, attributes(a), b)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^-^^
    |                                        |
    |                                        didn't expect any arguments here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[proc_macro_derive(d4, attributes(a), b)]
@@ -61,13 +65,14 @@ LL + #[proc_macro_derive(TraitName, attributes(name1, name2, ...))]
    |
 
 error[E0565]: malformed `proc_macro_derive` attribute input
-  --> $DIR/attribute.rs:29:1
+  --> $DIR/attribute.rs:33:1
    |
 LL | #[proc_macro_derive("a")]
    | ^^^^^^^^^^^^^^^^^^^^---^^
    |                     |
    |                     didn't expect a literal here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[proc_macro_derive("a")]
@@ -78,13 +83,14 @@ LL + #[proc_macro_derive(TraitName, attributes(name1, name2, ...))]
    |
 
 error[E0565]: malformed `proc_macro_derive` attribute input
-  --> $DIR/attribute.rs:34:1
+  --> $DIR/attribute.rs:39:1
    |
 LL | #[proc_macro_derive(d6 = "")]
    | ^^^^^^^^^^^^^^^^^^^^^^^----^^
    |                        |
    |                        didn't expect any arguments here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[proc_macro_derive(d6 = "")]
@@ -95,13 +101,14 @@ LL + #[proc_macro_derive(TraitName, attributes(name1, name2, ...))]
    |
 
 error[E0539]: malformed `proc_macro_derive` attribute input
-  --> $DIR/attribute.rs:39:1
+  --> $DIR/attribute.rs:45:1
    |
 LL | #[proc_macro_derive(m::d7)]
    | ^^^^^^^^^^^^^^^^^^^^-----^^
    |                     |
    |                     expected a valid identifier here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[proc_macro_derive(m::d7)]
@@ -112,13 +119,14 @@ LL + #[proc_macro_derive(TraitName, attributes(name1, name2, ...))]
    |
 
 error[E0565]: malformed `proc_macro_derive` attribute input
-  --> $DIR/attribute.rs:44:1
+  --> $DIR/attribute.rs:51:1
    |
 LL | #[proc_macro_derive(d8(a))]
    | ^^^^^^^^^^^^^^^^^^^^^^---^^
    |                       |
    |                       didn't expect any arguments here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[proc_macro_derive(d8(a))]
@@ -128,31 +136,33 @@ LL - #[proc_macro_derive(d8(a))]
 LL + #[proc_macro_derive(TraitName, attributes(name1, name2, ...))]
    |
 
-error[E0539]: malformed `proc_macro_derive` attribute input
-  --> $DIR/attribute.rs:49:1
-   |
-LL | #[proc_macro_derive(self)]
-   | ^^^^^^^^^^^^^^^^^^^^----^^
-   |                     |
-   |                     expected a valid identifier here
-   |
-help: try changing it to one of the following valid forms of the attribute
-   |
-LL - #[proc_macro_derive(self)]
-LL + #[proc_macro_derive(TraitName)]
-   |
-LL - #[proc_macro_derive(self)]
-LL + #[proc_macro_derive(TraitName, attributes(name1, name2, ...))]
-   |
-
 error[E0539]: malformed `proc_macro_derive` attribute input
   --> $DIR/attribute.rs:57:1
    |
+LL | #[proc_macro_derive(self)]
+   | ^^^^^^^^^^^^^^^^^^^^----^^
+   |                     |
+   |                     expected a valid identifier here
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros>
+help: try changing it to one of the following valid forms of the attribute
+   |
+LL - #[proc_macro_derive(self)]
+LL + #[proc_macro_derive(TraitName)]
+   |
+LL - #[proc_macro_derive(self)]
+LL + #[proc_macro_derive(TraitName, attributes(name1, name2, ...))]
+   |
+
+error[E0539]: malformed `proc_macro_derive` attribute input
+  --> $DIR/attribute.rs:66:1
+   |
 LL | #[proc_macro_derive(d11, a)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^-^^
    |                          |
    |                          the only valid argument here is `attributes`
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[proc_macro_derive(d11, a)]
@@ -163,13 +173,14 @@ LL + #[proc_macro_derive(TraitName, attributes(name1, name2, ...))]
    |
 
 error[E0539]: malformed `proc_macro_derive` attribute input
-  --> $DIR/attribute.rs:62:1
+  --> $DIR/attribute.rs:72:1
    |
 LL | #[proc_macro_derive(d12, attributes)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^----------^^
    |                          |
    |                          expected this to be a list
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[proc_macro_derive(d12, attributes)]
@@ -180,13 +191,14 @@ LL + #[proc_macro_derive(TraitName, attributes(name1, name2, ...))]
    |
 
 error[E0539]: malformed `proc_macro_derive` attribute input
-  --> $DIR/attribute.rs:67:1
+  --> $DIR/attribute.rs:78:1
    |
 LL | #[proc_macro_derive(d13, attributes("a"))]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^---^^^
    |                                     |
    |                                     expected a valid identifier here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[proc_macro_derive(d13, attributes("a"))]
@@ -197,13 +209,14 @@ LL + #[proc_macro_derive(TraitName, attributes(name1, name2, ...))]
    |
 
 error[E0565]: malformed `proc_macro_derive` attribute input
-  --> $DIR/attribute.rs:72:1
+  --> $DIR/attribute.rs:84:1
    |
 LL | #[proc_macro_derive(d14, attributes(a = ""))]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^----^^^
    |                                       |
    |                                       didn't expect any arguments here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[proc_macro_derive(d14, attributes(a = ""))]
@@ -214,13 +227,14 @@ LL + #[proc_macro_derive(TraitName, attributes(name1, name2, ...))]
    |
 
 error[E0539]: malformed `proc_macro_derive` attribute input
-  --> $DIR/attribute.rs:77:1
+  --> $DIR/attribute.rs:90:1
    |
 LL | #[proc_macro_derive(d15, attributes(m::a))]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^----^^^
    |                                     |
    |                                     expected a valid identifier here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[proc_macro_derive(d15, attributes(m::a))]
@@ -231,13 +245,14 @@ LL + #[proc_macro_derive(TraitName, attributes(name1, name2, ...))]
    |
 
 error[E0565]: malformed `proc_macro_derive` attribute input
-  --> $DIR/attribute.rs:82:1
+  --> $DIR/attribute.rs:96:1
    |
 LL | #[proc_macro_derive(d16, attributes(a(b)))]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^---^^^
    |                                      |
    |                                      didn't expect any arguments here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[proc_macro_derive(d16, attributes(a(b)))]
@@ -248,13 +263,14 @@ LL + #[proc_macro_derive(TraitName, attributes(name1, name2, ...))]
    |
 
 error[E0539]: malformed `proc_macro_derive` attribute input
-  --> $DIR/attribute.rs:87:1
+  --> $DIR/attribute.rs:102:1
    |
 LL | #[proc_macro_derive(d17, attributes(self))]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^----^^^
    |                                     |
    |                                     expected a valid identifier here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[proc_macro_derive(d17, attributes(self))]

tests/ui/repr/repr.stderr

@@ -4,6 +4,7 @@ error[E0539]: malformed `repr` attribute input
 LL | #[repr]
    | ^^^^^^^ expected this to be a list
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/type-layout.html#representations>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL | #[repr(<integer type>)]
@@ -22,6 +23,7 @@ error[E0539]: malformed `repr` attribute input
 LL | #[repr = "B"]
    | ^^^^^^^^^^^^^ expected this to be a list
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/type-layout.html#representations>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[repr = "B"]
@@ -44,6 +46,7 @@ error[E0539]: malformed `repr` attribute input
 LL | #[repr = "C"]
    | ^^^^^^^^^^^^^ expected this to be a list
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/type-layout.html#representations>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[repr = "C"]

tests/ui/resolve/path-attr-in-const-block.stderr

@@ -12,6 +12,8 @@ LL |         #![path = foo!()]
    |         |         |
    |         |         expected a string literal here
    |         help: must be of the form: `#[path = "file"]`
+   |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/items/modules.html#the-path-attribute>
 
 error: aborting due to 2 previous errors
 

tests/ui/span/E0539.stderr

@@ -6,6 +6,7 @@ LL | #[inline(unknown)]
    |          |
    |          valid arguments are `always` or `never`
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/attributes/codegen.html#the-inline-attribute>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[inline(unknown)]

tests/ui/test-attrs/test-should-panic-attr.rs

@@ -10,6 +10,7 @@ fn test1() {
 #[should_panic(expected)]
 //~^ ERROR malformed `should_panic` attribute input
 //~| NOTE expected this to be of the form `expected = "..."`
+//~| NOTE for more information, visit
 fn test2() {
     panic!();
 }
@@ -18,6 +19,7 @@ fn test2() {
 #[should_panic(expect)]
 //~^ ERROR malformed `should_panic` attribute input
 //~| NOTE the only valid argument here is "expected"
+//~| NOTE for more information, visit
 fn test3() {
     panic!();
 }
@@ -26,6 +28,7 @@ fn test3() {
 #[should_panic(expected(foo, bar))]
 //~^ ERROR malformed `should_panic` attribute input
 //~| NOTE expected this to be of the form `expected = "..."`
+//~| NOTE for more information, visit
 fn test4() {
     panic!();
 }
@@ -34,6 +37,7 @@ fn test4() {
 #[should_panic(expected = "foo", bar)]
 //~^ ERROR malformed `should_panic` attribute input
 //~| NOTE expected a single argument here
+//~| NOTE for more information, visit
 fn test5() {
     panic!();
 }

tests/ui/test-attrs/test-should-panic-attr.stderr

@@ -6,6 +6,7 @@ LL | #[should_panic(expected)]
    |                |
    |                expected this to be of the form `expected = "..."`
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/attributes/testing.html#the-should_panic-attribute>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[should_panic(expected)]
@@ -18,13 +19,14 @@ LL + #[should_panic]
    |
 
 error[E0539]: malformed `should_panic` attribute input
-  --> $DIR/test-should-panic-attr.rs:18:1
+  --> $DIR/test-should-panic-attr.rs:19:1
    |
 LL | #[should_panic(expect)]
    | ^^^^^^^^^^^^^^--------^
    |               |
    |               the only valid argument here is "expected"
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/attributes/testing.html#the-should_panic-attribute>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[should_panic(expect)]
@@ -37,13 +39,14 @@ LL + #[should_panic]
    |
 
 error[E0539]: malformed `should_panic` attribute input
-  --> $DIR/test-should-panic-attr.rs:26:1
+  --> $DIR/test-should-panic-attr.rs:28:1
    |
 LL | #[should_panic(expected(foo, bar))]
    | ^^^^^^^^^^^^^^^------------------^^
    |                |
    |                expected this to be of the form `expected = "..."`
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/attributes/testing.html#the-should_panic-attribute>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[should_panic(expected(foo, bar))]
@@ -57,13 +60,14 @@ LL + #[should_panic]
    |
 
 error[E0805]: malformed `should_panic` attribute input
-  --> $DIR/test-should-panic-attr.rs:34:1
+  --> $DIR/test-should-panic-attr.rs:37:1
    |
 LL | #[should_panic(expected = "foo", bar)]
    | ^^^^^^^^^^^^^^-----------------------^
    |               |
    |               expected a single argument here
    |
+   = note: for more information, visit <https://doc.rust-lang.org/reference/attributes/testing.html#the-should_panic-attribute>
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[should_panic(expected = "foo", bar)]