Stop using IllFormedAttributeInputLint for macro_use

JonathanBrouwer · JonathanBrouwer · commit b83522877264 · 2025-12-13T13:44:57.000+01:00
diff --git a/compiler/rustc_attr_parsing/src/attributes/macro_attrs.rs b/compiler/rustc_attr_parsing/src/attributes/macro_attrs.rs
@@ -3,7 +3,7 @@ use rustc_hir::attrs::MacroUseArgs;
 use rustc_session::lint::builtin::INVALID_MACRO_EXPORT_ARGUMENTS;
 
 use super::prelude::*;
-use crate::session_diagnostics::IllFormedAttributeInputLint;
+use crate::session_diagnostics::{AttributeParseErrorReason, IllFormedAttributeInputLint};
 
 pub(crate) struct MacroEscapeParser;
 impl<S: Stage> NoArgsAttributeParser<S> for MacroEscapeParser {
@@ -102,14 +102,7 @@ impl<S: Stage> AttributeParser<S> for MacroUseParser {
                     }
                 }
                 ArgParser::NameValue(_) => {
-                    let suggestions = cx.suggestions();
-                    cx.emit_err(IllFormedAttributeInputLint {
-                        num_suggestions: suggestions.len(),
-                        suggestions: DiagArgValue::StrListSepByAnd(
-                            suggestions.into_iter().map(|s| format!("`{s}`").into()).collect(),
-                        ),
-                        span,
-                    });
+                    cx.emit_parse_error(span, AttributeParseErrorReason::ExpectedListOrNoArgs);
                 }
             }
         },
diff --git a/compiler/rustc_attr_parsing/src/context.rs b/compiler/rustc_attr_parsing/src/context.rs
@@ -425,7 +425,7 @@ impl<'f, 'sess: 'f, S: Stage> SharedContext<'f, 'sess, S> {
 }
 
 impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
-    fn emit_parse_error(
+    pub(crate) fn emit_parse_error(
         &self,
         span: Span,
         reason: AttributeParseErrorReason<'_>,
diff --git a/compiler/rustc_attr_parsing/src/session_diagnostics.rs b/compiler/rustc_attr_parsing/src/session_diagnostics.rs
@@ -519,6 +519,7 @@ pub(crate) enum AttributeParseErrorReason<'a> {
     ExpectedAtLeastOneArgument,
     ExpectedSingleArgument,
     ExpectedList,
+    ExpectedListOrNoArgs,
     UnexpectedLiteral,
     ExpectedNameValue(Option<Symbol>),
     DuplicateKey(Symbol),
@@ -591,6 +592,9 @@ impl<'a, G: EmissionGuarantee> Diagnostic<'a, G> for AttributeParseError<'_> {
             AttributeParseErrorReason::ExpectedList => {
                 diag.span_label(self.span, "expected this to be a list");
             }
+            AttributeParseErrorReason::ExpectedListOrNoArgs => {
+                diag.span_label(self.span, "expected a list or no arguments here");
+            }
             AttributeParseErrorReason::DuplicateKey(key) => {
                 diag.span_label(self.span, format!("found `{key}` used as a key more than once"));
                 diag.code(E0538);
diff --git a/tests/ui/attributes/invalid-macro-use.rs b/tests/ui/attributes/invalid-macro-use.rs
@@ -2,7 +2,9 @@
 //~^ NOTE the lint level is defined here
 
 #[macro_use = 5]
-//~^ ERROR valid forms for the attribute are `#[macro_use(name1, name2, ...)]` and `#[macro_use]`
+//~^ ERROR malformed `macro_use` attribute input
+//~| NOTE expected a list or no arguments here
+//~| NOTE for more information, visit
 extern crate std as s1;
 
 #[macro_use(5)]
diff --git a/tests/ui/attributes/invalid-macro-use.stderr b/tests/ui/attributes/invalid-macro-use.stderr
@@ -1,23 +1,33 @@
 error[E0469]: imported macro not found
-  --> $DIR/invalid-macro-use.rs:51:13
+  --> $DIR/invalid-macro-use.rs:53:13
    |
 LL | #[macro_use(a)]
    |             ^
 
 error[E0469]: imported macro not found
-  --> $DIR/invalid-macro-use.rs:53:13
+  --> $DIR/invalid-macro-use.rs:55:13
    |
 LL | #[macro_use(b)]
    |             ^
 
-error: valid forms for the attribute are `#[macro_use(name1, name2, ...)]` and `#[macro_use]`
+error[E0539]: malformed `macro_use` attribute input
   --> $DIR/invalid-macro-use.rs:4:1
    |
 LL | #[macro_use = 5]
-   | ^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^ expected a list or no 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 = 5]
+LL + #[macro_use(name1, name2, ...)]
+   |
+LL - #[macro_use = 5]
+LL + #[macro_use]
+   |
 
 error[E0539]: malformed `macro_use` attribute input
-  --> $DIR/invalid-macro-use.rs:8:1
+  --> $DIR/invalid-macro-use.rs:10:1
    |
 LL | #[macro_use(5)]
    | ^^^^^^^^^^^^-^^
@@ -35,7 +45,7 @@ LL + #[macro_use]
    |
 
 error[E0565]: malformed `macro_use` attribute input
-  --> $DIR/invalid-macro-use.rs:14:1
+  --> $DIR/invalid-macro-use.rs:16:1
    |
 LL | #[macro_use(a = "b")]
    | ^^^^^^^^^^^^^^-----^^
@@ -53,7 +63,7 @@ LL + #[macro_use]
    |
 
 error[E0565]: malformed `macro_use` attribute input
-  --> $DIR/invalid-macro-use.rs:20:1
+  --> $DIR/invalid-macro-use.rs:22:1
    |
 LL | #[macro_use(a(b))]
    | ^^^^^^^^^^^^^---^^
@@ -71,7 +81,7 @@ LL + #[macro_use]
    |
 
 error[E0539]: malformed `macro_use` attribute input
-  --> $DIR/invalid-macro-use.rs:26:1
+  --> $DIR/invalid-macro-use.rs:28:1
    |
 LL | #[macro_use(a::b)]
    | ^^^^^^^^^^^^----^^
@@ -89,13 +99,13 @@ LL + #[macro_use]
    |
 
 error: unused attribute
-  --> $DIR/invalid-macro-use.rs:32:1
+  --> $DIR/invalid-macro-use.rs:34:1
    |
 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:36:1
    |
 LL | #[macro_use]
    | ^^^^^^^^^^^^
@@ -106,25 +116,25 @@ LL | #![deny(unused_attributes)]
    |         ^^^^^^^^^^^^^^^^^
 
 error: unused attribute
-  --> $DIR/invalid-macro-use.rs:40:1
+  --> $DIR/invalid-macro-use.rs:42:1
    |
 LL | #[macro_use(a)]
    | ^^^^^^^^^^^^^^^ help: remove this attribute
    |
 note: attribute also specified here
-  --> $DIR/invalid-macro-use.rs:38:1
+  --> $DIR/invalid-macro-use.rs:40:1
    |
 LL | #[macro_use]
    | ^^^^^^^^^^^^
 
 error: unused attribute
-  --> $DIR/invalid-macro-use.rs:46:1
+  --> $DIR/invalid-macro-use.rs:48:1
    |
 LL | #[macro_use]
    | ^^^^^^^^^^^^ help: remove this attribute
    |
 note: attribute also specified here
-  --> $DIR/invalid-macro-use.rs:44:1
+  --> $DIR/invalid-macro-use.rs:46:1
    |
 LL | #[macro_use]
    | ^^^^^^^^^^^^
diff --git a/tests/ui/attributes/malformed-attrs.rs b/tests/ui/attributes/malformed-attrs.rs
@@ -214,7 +214,7 @@ static mut TLS: u8 = 42;
 #[no_link()]
 //~^ ERROR malformed
 #[macro_use = 1]
-//~^ ERROR valid forms for the attribute are `#[macro_use(name1, name2, ...)]` and `#[macro_use]`
+//~^ ERROR malformed
 extern crate wloop;
 //~^ ERROR can't find crate for `wloop` [E0463]
 
diff --git a/tests/ui/attributes/malformed-attrs.stderr b/tests/ui/attributes/malformed-attrs.stderr
@@ -614,11 +614,21 @@ LL | #[non_exhaustive = 1]
    | |                didn't expect any arguments here
    | help: must be of the form: `#[non_exhaustive]`
 
-error: valid forms for the attribute are `#[macro_use(name1, name2, ...)]` and `#[macro_use]`
+error[E0539]: malformed `macro_use` attribute input
   --> $DIR/malformed-attrs.rs:216:1
    |
 LL | #[macro_use = 1]
-   | ^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^ expected a list or no 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 = 1]
+LL + #[macro_use(name1, name2, ...)]
+   |
+LL - #[macro_use = 1]
+LL + #[macro_use]
+   |
 
 error: valid forms for the attribute are `#[macro_export(local_inner_macros)]` and `#[macro_export]`
   --> $DIR/malformed-attrs.rs:221:1
diff --git a/tests/ui/feature-gates/issue-43106-gating-of-macro_use.rs b/tests/ui/feature-gates/issue-43106-gating-of-macro_use.rs
@@ -13,7 +13,7 @@ mod macro_escape {
     //~^ ERROR arguments to `macro_use` are not allowed here
 
     #[macro_use = "2700"] struct S;
-    //~^ ERROR valid forms for the attribute are `#[macro_use(name1, name2, ...)]` and `#[macro_use]`
+    //~^ ERROR malformed
     //~| WARN cannot be used on
     //~| WARN previously accepted
 
diff --git a/tests/ui/feature-gates/issue-43106-gating-of-macro_use.stderr b/tests/ui/feature-gates/issue-43106-gating-of-macro_use.stderr
@@ -16,11 +16,21 @@ error: arguments to `macro_use` are not allowed here
 LL | #![macro_use(my_macro)]
    | ^^^^^^^^^^^^^^^^^^^^^^^
 
-error: valid forms for the attribute are `#[macro_use(name1, name2, ...)]` and `#[macro_use]`
+error[E0539]: malformed `macro_use` attribute input
   --> $DIR/issue-43106-gating-of-macro_use.rs:15:5
    |
 LL |     #[macro_use = "2700"] struct S;
-   |     ^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^ expected a list or no 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 = "2700"] struct S;
+LL +     #[macro_use(name1, name2, ...)] struct S;
+   |
+LL -     #[macro_use = "2700"] struct S;
+LL +     #[macro_use] struct S;
+   |
 
 warning: `#[macro_use]` attribute cannot be used on structs
   --> $DIR/issue-43106-gating-of-macro_use.rs:15:5
@@ -61,3 +71,4 @@ LL |     #[macro_use] impl S { }
 
 error: aborting due to 4 previous errors; 4 warnings emitted
 
+For more information about this error, try `rustc --explain E0539`.

Original file line number	Diff line number	Diff line change
`@@ -3,7 +3,7 @@ use rustc_hir::attrs::MacroUseArgs;`
`3`	`3`	`use rustc_session::lint::builtin::INVALID_MACRO_EXPORT_ARGUMENTS;`
`4`	`4`
`5`	`5`	`use super::prelude::*;`
`6`		`-use crate::session_diagnostics::IllFormedAttributeInputLint;`
	`6`	`+use crate::session_diagnostics::{AttributeParseErrorReason, IllFormedAttributeInputLint};`
`7`	`7`
`8`	`8`	`pub(crate) struct MacroEscapeParser;`
`9`	`9`	`impl<S: Stage> NoArgsAttributeParser<S> for MacroEscapeParser {`
`@@ -102,14 +102,7 @@ impl<S: Stage> AttributeParser<S> for MacroUseParser {`
`102`	`102`	`}`
`103`	`103`	`}`
`104`	`104`	`ArgParser::NameValue(_) => {`
`105`		`- let suggestions = cx.suggestions();`
`106`		`- cx.emit_err(IllFormedAttributeInputLint {`
`107`		`- num_suggestions: suggestions.len(),`
`108`		`- suggestions: DiagArgValue::StrListSepByAnd(`
`109`		- suggestions.into_iter().map(\|s\| format!("`{s}`").into()).collect(),
`110`		`- ),`
`111`		`- span,`
`112`		`- });`
	`105`	`+ cx.emit_parse_error(span, AttributeParseErrorReason::ExpectedListOrNoArgs);`
`113`	`106`	`}`
`114`	`107`	`}`
`115`	`108`	`},`
Original file line number	Diff line number	Diff line change
`@@ -425,7 +425,7 @@ impl<'f, 'sess: 'f, S: Stage> SharedContext<'f, 'sess, S> {`
`425`	`425`	`}`
`426`	`426`
`427`	`427`	`impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {`
`428`		`- fn emit_parse_error(`
	`428`	`+ pub(crate) fn emit_parse_error(`
`429`	`429`	`&self,`
`430`	`430`	`span: Span,`
`431`	`431`	`reason: AttributeParseErrorReason<'_>,`
Original file line number	Diff line number	Diff line change
`@@ -1,23 +1,33 @@`
`1`	`1`	`error[E0469]: imported macro not found`
`2`		`- --> $DIR/invalid-macro-use.rs:51:13`
	`2`	`+ --> $DIR/invalid-macro-use.rs:53:13`
`3`	`3`	`\|`
`4`	`4`	`LL \| #[macro_use(a)]`
`5`	`5`	`\| ^`
`6`	`6`
`7`	`7`	`error[E0469]: imported macro not found`
`8`		`- --> $DIR/invalid-macro-use.rs:53:13`
	`8`	`+ --> $DIR/invalid-macro-use.rs:55:13`
`9`	`9`	`\|`
`10`	`10`	`LL \| #[macro_use(b)]`
`11`	`11`	`\| ^`
`12`	`12`
`13`		-error: valid forms for the attribute are `#[macro_use(name1, name2, ...)]` and `#[macro_use]`
	`13`	+error[E0539]: malformed `macro_use` attribute input
`14`	`14`	`--> $DIR/invalid-macro-use.rs:4:1`
`15`	`15`	`\|`
`16`	`16`	`LL \| #[macro_use = 5]`
`17`		`- \| ^^^^^^^^^^^^^^^^`
	`17`	`+ \| ^^^^^^^^^^^^^^^^ expected a list or no arguments here`
	`18`	`+ \|`
	`19`	`+ = note: for more information, visit <https://doc.rust-lang.org/reference/macros-by-example.html#the-macro_use-attribute>`
	`20`	`+help: try changing it to one of the following valid forms of the attribute`
	`21`	`+ \|`
	`22`	`+LL - #[macro_use = 5]`
	`23`	`+LL + #[macro_use(name1, name2, ...)]`
	`24`	`+ \|`
	`25`	`+LL - #[macro_use = 5]`
	`26`	`+LL + #[macro_use]`
	`27`	`+ \|`
`18`	`28`
`19`	`29`	error[E0539]: malformed `macro_use` attribute input
`20`		`- --> $DIR/invalid-macro-use.rs:8:1`
	`30`	`+ --> $DIR/invalid-macro-use.rs:10:1`
`21`	`31`	`\|`
`22`	`32`	`LL \| #[macro_use(5)]`
`23`	`33`	`\| ^^^^^^^^^^^^-^^`
`@@ -35,7 +45,7 @@ LL + #[macro_use]`
`35`	`45`	`\|`
`36`	`46`
`37`	`47`	error[E0565]: malformed `macro_use` attribute input
`38`		`- --> $DIR/invalid-macro-use.rs:14:1`
	`48`	`+ --> $DIR/invalid-macro-use.rs:16:1`
`39`	`49`	`\|`
`40`	`50`	`LL \| #[macro_use(a = "b")]`
`41`	`51`	`\| ^^^^^^^^^^^^^^-----^^`
`@@ -53,7 +63,7 @@ LL + #[macro_use]`
`53`	`63`	`\|`
`54`	`64`
`55`	`65`	error[E0565]: malformed `macro_use` attribute input
`56`		`- --> $DIR/invalid-macro-use.rs:20:1`
	`66`	`+ --> $DIR/invalid-macro-use.rs:22:1`
`57`	`67`	`\|`
`58`	`68`	`LL \| #[macro_use(a(b))]`
`59`	`69`	`\| ^^^^^^^^^^^^^---^^`
`@@ -71,7 +81,7 @@ LL + #[macro_use]`
`71`	`81`	`\|`
`72`	`82`
`73`	`83`	error[E0539]: malformed `macro_use` attribute input
`74`		`- --> $DIR/invalid-macro-use.rs:26:1`
	`84`	`+ --> $DIR/invalid-macro-use.rs:28:1`
`75`	`85`	`\|`
`76`	`86`	`LL \| #[macro_use(a::b)]`
`77`	`87`	`\| ^^^^^^^^^^^^----^^`
`@@ -89,13 +99,13 @@ LL + #[macro_use]`
`89`	`99`	`\|`
`90`	`100`
`91`	`101`	`error: unused attribute`
`92`		`- --> $DIR/invalid-macro-use.rs:32:1`
	`102`	`+ --> $DIR/invalid-macro-use.rs:34:1`
`93`	`103`	`\|`
`94`	`104`	`LL \| #[macro_use(a)]`
`95`	`105`	`\| ^^^^^^^^^^^^^^^ help: remove this attribute`
`96`	`106`	`\|`
`97`	`107`	`note: attribute also specified here`
`98`		`- --> $DIR/invalid-macro-use.rs:34:1`
	`108`	`+ --> $DIR/invalid-macro-use.rs:36:1`
`99`	`109`	`\|`
`100`	`110`	`LL \| #[macro_use]`
`101`	`111`	`\| ^^^^^^^^^^^^`
`@@ -106,25 +116,25 @@ LL \| #![deny(unused_attributes)]`
`106`	`116`	`\| ^^^^^^^^^^^^^^^^^`
`107`	`117`
`108`	`118`	`error: unused attribute`
`109`		`- --> $DIR/invalid-macro-use.rs:40:1`
	`119`	`+ --> $DIR/invalid-macro-use.rs:42:1`
`110`	`120`	`\|`
`111`	`121`	`LL \| #[macro_use(a)]`
`112`	`122`	`\| ^^^^^^^^^^^^^^^ help: remove this attribute`
`113`	`123`	`\|`
`114`	`124`	`note: attribute also specified here`
`115`		`- --> $DIR/invalid-macro-use.rs:38:1`
	`125`	`+ --> $DIR/invalid-macro-use.rs:40:1`
`116`	`126`	`\|`
`117`	`127`	`LL \| #[macro_use]`
`118`	`128`	`\| ^^^^^^^^^^^^`
`119`	`129`
`120`	`130`	`error: unused attribute`
`121`		`- --> $DIR/invalid-macro-use.rs:46:1`
	`131`	`+ --> $DIR/invalid-macro-use.rs:48:1`
`122`	`132`	`\|`
`123`	`133`	`LL \| #[macro_use]`
`124`	`134`	`\| ^^^^^^^^^^^^ help: remove this attribute`
`125`	`135`	`\|`
`126`	`136`	`note: attribute also specified here`
`127`		`- --> $DIR/invalid-macro-use.rs:44:1`
	`137`	`+ --> $DIR/invalid-macro-use.rs:46:1`
`128`	`138`	`\|`
`129`	`139`	`LL \| #[macro_use]`
`130`	`140`	`\| ^^^^^^^^^^^^`