Improve workings of attribute suggestions

compiler/rustc_attr_parsing/src/attributes/cfg.rs

@@ -27,8 +27,7 @@ use crate::session_diagnostics::{
     ParsedDescription,
 };
 use crate::{
-    AttrSuggestionStyle, AttributeParser, AttributeTemplate, check_cfg, parse_version,
-    session_diagnostics, template,
+    AttributeParser, AttributeTemplate, check_cfg, parse_version, session_diagnostics, template,
 };
 
 pub const CFG_TEMPLATE: AttributeTemplate = template!(
@@ -329,12 +328,12 @@ pub fn parse_cfg_attr(
                 Ok(r) => return Some(r),
                 Err(e) => {
                     let suggestions = CFG_ATTR_TEMPLATE.suggestions(
-                        AttrSuggestionStyle::Attribute(cfg_attr.style),
+                        ParsedDescription::Attribute,
                         cfg_attr.get_normal_item().unsafety,
                         sym::cfg_attr,
                     );
                     e.with_span_suggestions(
-                        cfg_attr.span,
+                        cfg_attr.get_normal_item().span,
                         "must be of the form",
                         suggestions,
                         Applicability::HasPlaceholders,
@@ -358,15 +357,14 @@ pub fn parse_cfg_attr(
 
             sess.dcx().emit_err(AttributeParseError {
                 span,
-                attr_span: cfg_attr.span,
                 inner_span: cfg_attr.get_normal_item().span,
                 template: CFG_ATTR_TEMPLATE,
                 path: AttrPath::from_ast(&cfg_attr.get_normal_item().path, identity),
                 description: ParsedDescription::Attribute,
                 reason,
                 suggestions: session_diagnostics::AttributeParseErrorSuggestions::CreatedByTemplate(
                     CFG_ATTR_TEMPLATE.suggestions(
-                        AttrSuggestionStyle::Attribute(cfg_attr.style),
+                        ParsedDescription::Attribute,
                         cfg_attr.get_normal_item().unsafety,
                         sym::cfg_attr,
                     ),

compiler/rustc_attr_parsing/src/attributes/doc.rs

@@ -728,7 +728,7 @@ impl DocParser {
         match args {
             ArgParser::NoArgs => {
                 let suggestions = cx.adcx().suggestions();
-                let span = cx.attr_span;
+                let span = cx.inner_span;
                 cx.emit_lint(
                     rustc_session::lint::builtin::INVALID_DOC_ATTRIBUTES,
                     IllFormedAttributeInput::new(&suggestions, None, None),

compiler/rustc_attr_parsing/src/context.rs

@@ -75,7 +75,7 @@ use crate::session_diagnostics::{
     ParsedDescription, UnusedDuplicate,
 };
 use crate::target_checking::AllowedTargets;
-use crate::{AttrSuggestionStyle, AttributeParser, AttributeTemplate, EmitAttribute};
+use crate::{AttributeParser, AttributeTemplate, EmitAttribute};
 
 type GroupType = LazyLock<GroupTypeInner>;
 
@@ -920,7 +920,7 @@ impl<'a, 'f, 'sess: 'f> AttributeDiagnosticContext<'a, 'f, 'sess> {
         reason: AttributeParseErrorReason<'_>,
     ) -> ErrorGuaranteed {
         let suggestions = if self.custom_suggestions.is_empty() {
-            AttributeParseErrorSuggestions::CreatedByTemplate(self.template_suggestions())
+            AttributeParseErrorSuggestions::CreatedByTemplate(self.suggestions())
         } else {
             AttributeParseErrorSuggestions::CreatedByParser(mem::take(&mut self.custom_suggestions))
         };
@@ -933,7 +933,6 @@ impl<'a, 'f, 'sess: 'f> AttributeDiagnosticContext<'a, 'f, 'sess> {
 
         self.emit_err(AttributeParseError {
             span,
-            attr_span: self.attr_span,
             inner_span: self.inner_span,
             template: *self.template,
             path: self.attr_path.clone(),
@@ -949,19 +948,6 @@ impl<'a, 'f, 'sess: 'f> AttributeDiagnosticContext<'a, 'f, 'sess> {
         self.custom_suggestions.push(Suggestion { msg, sp: span, code });
         self
     }
-
-    pub(crate) fn template_suggestions(&self) -> Vec<String> {
-        let style = match self.parsed_description {
-            // If the outer and inner spans are equal, we are parsing an embedded attribute
-            ParsedDescription::Attribute if self.attr_span == self.inner_span => {
-                AttrSuggestionStyle::EmbeddedAttribute
-            }
-            ParsedDescription::Attribute => AttrSuggestionStyle::Attribute(self.attr_style),
-            ParsedDescription::Macro => AttrSuggestionStyle::Macro,
-        };
-
-        self.template.suggestions(style, self.attr_safety, &self.attr_path)
-    }
 }
 
 /// Helpers that can be used to generate errors during attribute parsing.
@@ -1137,7 +1123,7 @@ impl<'a, 'f, 'sess: 'f> AttributeDiagnosticContext<'a, 'f, 'sess> {
         help: Option<String>,
     ) {
         let suggestions = self.suggestions();
-        let span = self.attr_span;
+        let span = self.inner_span;
         self.emit_lint(
             lint,
             crate::diagnostics::IllFormedAttributeInput::new(&suggestions, None, help.as_deref()),
@@ -1146,16 +1132,7 @@ impl<'a, 'f, 'sess: 'f> AttributeDiagnosticContext<'a, 'f, 'sess> {
     }
 
     pub(crate) fn suggestions(&self) -> Vec<String> {
-        let style = match self.parsed_description {
-            // If the outer and inner spans are equal, we are parsing an embedded attribute
-            ParsedDescription::Attribute if self.attr_span == self.inner_span => {
-                AttrSuggestionStyle::EmbeddedAttribute
-            }
-            ParsedDescription::Attribute => AttrSuggestionStyle::Attribute(self.attr_style),
-            ParsedDescription::Macro => AttrSuggestionStyle::Macro,
-        };
-
-        self.template.suggestions(style, self.attr_safety, &self.attr_path)
+        self.template.suggestions(self.parsed_description, self.attr_safety, &self.attr_path)
     }
     /// Error that a string literal was expected.
     /// You can optionally give the literal you did find (which you found not to be a string literal)

compiler/rustc_attr_parsing/src/lib.rs

@@ -119,4 +119,4 @@ pub use context::{OmitDoc, ShouldEmit};
 pub use interface::{AttributeParser, EmitAttribute};
 pub use rustc_parse::parser::Recovery;
 pub use session_diagnostics::ParsedDescription;
-pub use template::{AttrSuggestionStyle, AttributeTemplate};
+pub use template::AttributeTemplate;

compiler/rustc_attr_parsing/src/session_diagnostics.rs

@@ -509,7 +509,6 @@ pub enum ParsedDescription {
 
 pub(crate) struct AttributeParseError<'a> {
     pub(crate) span: Span,
-    pub(crate) attr_span: Span,
     pub(crate) inner_span: Span,
     pub(crate) template: AttributeTemplate,
     pub(crate) path: AttrPath,
@@ -604,7 +603,7 @@ impl<'a> AttributeParseError<'a> {
         match &self.suggestions {
             AttributeParseErrorSuggestions::CreatedByTemplate(suggestions) => {
                 diag.span_suggestions(
-                        self.attr_span,
+                        self.inner_span,
                         if suggestions.len() == 1 {
                             "must be of the form".to_string()
                         } else {

compiler/rustc_attr_parsing/src/template.rs

@@ -1,7 +1,8 @@
 use rustc_ast::ast::Safety;
-use rustc_hir::AttrStyle;
 use rustc_span::Symbol;
 
+use crate::ParsedDescription;
+
 /// A template to suggest the correct syntax of an attribute.
 ///
 /// This is not used to *check* attributes. The attribute's parser is responsible for that.
@@ -22,30 +23,16 @@ pub struct AttributeTemplate {
     pub docs: Option<&'static str>,
 }
 
-pub enum AttrSuggestionStyle {
-    /// The suggestion is styled for a normal attribute.
-    /// The `AttrStyle` determines whether this is an inner or outer attribute.
-    Attribute(AttrStyle),
-    /// The suggestion is styled for an attribute embedded into another attribute.
-    /// For example, attributes inside `#[cfg_attr(true, attr(...)]`.
-    EmbeddedAttribute,
-    /// The suggestion is styled for macros that are parsed with attribute parsers.
-    /// For example, the `cfg!(predicate)` macro.
-    Macro,
-}
-
 impl AttributeTemplate {
     pub fn suggestions(
         &self,
-        style: AttrSuggestionStyle,
+        description: ParsedDescription,
         safety: Safety,
         name: impl std::fmt::Display,
     ) -> Vec<String> {
-        let (start, macro_call, end) = match style {
-            AttrSuggestionStyle::Attribute(AttrStyle::Outer) => ("#[", "", "]"),
-            AttrSuggestionStyle::Attribute(AttrStyle::Inner) => ("#![", "", "]"),
-            AttrSuggestionStyle::Macro => ("", "!", ""),
-            AttrSuggestionStyle::EmbeddedAttribute => ("", "", ""),
+        let macro_call = match description {
+            ParsedDescription::Macro => "!",
+            ParsedDescription::Attribute => "",
         };
 
         let mut suggestions = vec![];
@@ -57,25 +44,20 @@ impl AttributeTemplate {
 
         if self.word {
             debug_assert!(macro_call.is_empty(), "Macro suggestions use list style");
-            suggestions.push(format!("{start}{safety_start}{name}{safety_end}{end}"));
+            suggestions.push(format!("{safety_start}{name}{safety_end}"));
         }
         if let Some(descr) = self.list {
             for descr in descr {
-                suggestions.push(format!(
-                    "{start}{safety_start}{name}{macro_call}({descr}){safety_end}{end}"
-                ));
+                suggestions.push(format!("{safety_start}{name}{macro_call}({descr}){safety_end}"));
             }
         }
         suggestions.extend(
-            self.one_of
-                .iter()
-                .map(|&word| format!("{start}{safety_start}{name}({word}){safety_end}{end}")),
+            self.one_of.iter().map(|&word| format!("{safety_start}{name}({word}){safety_end}")),
         );
         if let Some(descr) = self.name_value_str {
             debug_assert!(macro_call.is_empty(), "Macro suggestions use list style");
             for descr in descr {
-                suggestions
-                    .push(format!("{start}{safety_start}{name} = \"{descr}\"{safety_end}{end}"));
+                suggestions.push(format!("{safety_start}{name} = \"{descr}\"{safety_end}"));
             }
         }
         suggestions.sort();

tests/rustdoc-ui/lints/invalid-doc-attr-2.stderr

@@ -11,11 +11,11 @@ note: the lint level is defined here
 LL | #![deny(invalid_doc_attributes)]
    |         ^^^^^^^^^^^^^^^^^^^^^^
 
-error: valid forms for the attribute are `#![doc = "string"]`, `#![doc(alias)]`, `#![doc(attribute)]`, `#![doc(auto_cfg)]`, `#![doc(cfg)]`, `#![doc(fake_variadic)]`, `#![doc(hidden)]`, `#![doc(html_favicon_url)]`, `#![doc(html_logo_url)]`, `#![doc(html_no_source)]`, `#![doc(html_playground_url)]`, `#![doc(html_root_url)]`, `#![doc(include)]`, `#![doc(inline)]`, `#![doc(issue_tracker_base_url)]`, `#![doc(keyword)]`, `#![doc(masked)]`, `#![doc(no_default_passes)]`, `#![doc(no_inline)]`, `#![doc(notable_trait)]`, `#![doc(passes)]`, `#![doc(plugins)]`, `#![doc(rust_logo)]`, `#![doc(search_unbox)]`, `#![doc(spotlight)]`, and `#![doc(test)]`
-  --> $DIR/invalid-doc-attr-2.rs:6:1
+error: valid forms for the attribute are `doc = "string"`, `doc(alias)`, `doc(attribute)`, `doc(auto_cfg)`, `doc(cfg)`, `doc(fake_variadic)`, `doc(hidden)`, `doc(html_favicon_url)`, `doc(html_logo_url)`, `doc(html_no_source)`, `doc(html_playground_url)`, `doc(html_root_url)`, `doc(include)`, `doc(inline)`, `doc(issue_tracker_base_url)`, `doc(keyword)`, `doc(masked)`, `doc(no_default_passes)`, `doc(no_inline)`, `doc(notable_trait)`, `doc(passes)`, `doc(plugins)`, `doc(rust_logo)`, `doc(search_unbox)`, `doc(spotlight)`, and `doc(test)`
+  --> $DIR/invalid-doc-attr-2.rs:6:4
    |
 LL | #![doc]
-   | ^^^^^^^
+   |    ^^^
 
 error: aborting due to 2 previous errors
 

tests/ui/attributes/args-checked.stderr

@@ -38,13 +38,13 @@ LL | #[inline(always = 5)]
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[inline(always = 5)]
-LL + #[inline(always)]
+LL + #[inline]
    |
 LL - #[inline(always = 5)]
-LL + #[inline(never)]
+LL + #[inline(always)]
    |
 LL - #[inline(always = 5)]
-LL + #[inline]
+LL + #[inline(never)]
    |
 
 error[E0539]: malformed `inline` attribute input
@@ -59,13 +59,13 @@ LL | #[inline(always(x, y, z))]
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[inline(always(x, y, z))]
-LL + #[inline(always)]
+LL + #[inline]
    |
 LL - #[inline(always(x, y, z))]
-LL + #[inline(never)]
+LL + #[inline(always)]
    |
 LL - #[inline(always(x, y, z))]
-LL + #[inline]
+LL + #[inline(never)]
    |
 
 error[E0539]: malformed `instruction_set` attribute input
@@ -241,13 +241,13 @@ LL | #[used(always = 5)]
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[used(always = 5)]
-LL + #[used(compiler)]
+LL + #[used]
    |
 LL - #[used(always = 5)]
-LL + #[used(linker)]
+LL + #[used(compiler)]
    |
 LL - #[used(always = 5)]
-LL + #[used]
+LL + #[used(linker)]
    |
 
 error[E0539]: malformed `used` attribute input
@@ -261,13 +261,13 @@ LL | #[used(always(x, y, z))]
 help: try changing it to one of the following valid forms of the attribute
    |
 LL - #[used(always(x, y, z))]
-LL + #[used(compiler)]
+LL + #[used]
    |
 LL - #[used(always(x, y, z))]
-LL + #[used(linker)]
+LL + #[used(compiler)]
    |
 LL - #[used(always(x, y, z))]
-LL + #[used]
+LL + #[used(linker)]
    |
 
 error[E0565]: malformed `rustc_must_implement_one_of` attribute input
@@ -314,21 +314,21 @@ LL | #[rustc_dump_layout(debug(x, y, z))]
    |                     |
    |                     didn't expect a literal here
 
-error: valid forms for the attribute are `#[macro_export(local_inner_macros)]` and `#[macro_export]`
-  --> $DIR/args-checked.rs:37:1
+error: valid forms for the attribute are `macro_export` and `macro_export(local_inner_macros)`
+  --> $DIR/args-checked.rs:37:3
    |
 LL | #[macro_export(local_inner_macros = 5)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #57571 <https://github.com/rust-lang/rust/issues/57571>
    = note: `#[deny(invalid_macro_export_arguments)]` (part of `#[deny(future_incompatible)]`) on by default
 
-error: valid forms for the attribute are `#[macro_export(local_inner_macros)]` and `#[macro_export]`
-  --> $DIR/args-checked.rs:40:1
+error: valid forms for the attribute are `macro_export` and `macro_export(local_inner_macros)`
+  --> $DIR/args-checked.rs:40:3
    |
 LL | #[macro_export(local_inner_macros(x, y, z))]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #57571 <https://github.com/rust-lang/rust/issues/57571>
@@ -338,22 +338,22 @@ error: aborting due to 23 previous errors
 Some errors have detailed explanations: E0539, E0565.
 For more information about an error, try `rustc --explain E0539`.
 Future incompatibility report: Future breakage diagnostic:
-error: valid forms for the attribute are `#[macro_export(local_inner_macros)]` and `#[macro_export]`
-  --> $DIR/args-checked.rs:37:1
+error: valid forms for the attribute are `macro_export` and `macro_export(local_inner_macros)`
+  --> $DIR/args-checked.rs:37:3
    |
 LL | #[macro_export(local_inner_macros = 5)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #57571 <https://github.com/rust-lang/rust/issues/57571>
    = note: `#[deny(invalid_macro_export_arguments)]` (part of `#[deny(future_incompatible)]`) on by default
 
 Future breakage diagnostic:
-error: valid forms for the attribute are `#[macro_export(local_inner_macros)]` and `#[macro_export]`
-  --> $DIR/args-checked.rs:40:1
+error: valid forms for the attribute are `macro_export` and `macro_export(local_inner_macros)`
+  --> $DIR/args-checked.rs:40:3
    |
 LL | #[macro_export(local_inner_macros(x, y, z))]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #57571 <https://github.com/rust-lang/rust/issues/57571>

tests/ui/attributes/attribute-on-wrong-item-inline-repr.stderr

@@ -18,13 +18,13 @@ LL |     #[inline(XYZ)]
 help: try changing it to one of the following valid forms of the attribute
    |
 LL -     #[inline(XYZ)]
-LL +     #[inline(always)]
+LL +     #[inline]
    |
 LL -     #[inline(XYZ)]
-LL +     #[inline(never)]
+LL +     #[inline(always)]
    |
 LL -     #[inline(XYZ)]
-LL +     #[inline]
+LL +     #[inline(never)]
    |
 
 error: the `inline` attribute cannot be used on statements
@@ -75,13 +75,13 @@ LL |     #[inline(ABC)]
 help: try changing it to one of the following valid forms of the attribute
    |
 LL -     #[inline(ABC)]
-LL +     #[inline(always)]
+LL +     #[inline]
    |
 LL -     #[inline(ABC)]
-LL +     #[inline(never)]
+LL +     #[inline(always)]
    |
 LL -     #[inline(ABC)]
-LL +     #[inline]
+LL +     #[inline(never)]
    |
 
 error: the `inline` attribute cannot be used on expressions