Extract subdiagnostic attribute parsing

4 files changed, 402 insertions, 315 deletions

diff --git a/compiler/rustc_macros/src/diagnostics/subdiagnostic.rs b/compiler/rustc_macros/src/diagnostics/subdiagnostic.rs
index 9116dd186f9..9ea03e186e7 100644
--- a/compiler/rustc_macros/src/diagnostics/subdiagnostic.rs
+++ b/compiler/rustc_macros/src/diagnostics/subdiagnostic.rs
@@ -4,100 +4,16 @@ use crate::diagnostics::error::{
     span_err, throw_invalid_attr, throw_invalid_nested_attr, throw_span_err, DiagnosticDeriveError,
 };
 use crate::diagnostics::utils::{
-    report_error_if_not_applied_to_applicability, report_error_if_not_applied_to_span,
-    Applicability, FieldInfo, FieldInnerTy, HasFieldMap, SetOnce,
+    report_error_if_not_applied_to_applicability, report_error_if_not_applied_to_span, FieldInfo,
+    FieldInnerTy, HasFieldMap, SetOnce,
 };
 use proc_macro2::TokenStream;
 use quote::{format_ident, quote};
 use std::collections::HashMap;
-use std::fmt;
-use std::str::FromStr;
 use syn::{spanned::Spanned, Attribute, Meta, MetaList, MetaNameValue, NestedMeta, Path};
 use synstructure::{BindingInfo, Structure, VariantInfo};
 
-use super::utils::SpannedOption;
-
-/// Which kind of suggestion is being created?
-#[derive(Clone, Copy)]
-enum SubdiagnosticSuggestionKind {
-    /// `#[suggestion]`
-    Normal,
-    /// `#[suggestion_short]`
-    Short,
-    /// `#[suggestion_hidden]`
-    Hidden,
-    /// `#[suggestion_verbose]`
-    Verbose,
-}
-
-impl FromStr for SubdiagnosticSuggestionKind {
-    type Err = ();
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        match s {
-            "" => Ok(SubdiagnosticSuggestionKind::Normal),
-            "_short" => Ok(SubdiagnosticSuggestionKind::Short),
-            "_hidden" => Ok(SubdiagnosticSuggestionKind::Hidden),
-            "_verbose" => Ok(SubdiagnosticSuggestionKind::Verbose),
-            _ => Err(()),
-        }
-    }
-}
-
-impl SubdiagnosticSuggestionKind {
-    pub fn to_suggestion_style(&self) -> TokenStream {
-        match self {
-            SubdiagnosticSuggestionKind::Normal => {
-                quote! { rustc_errors::SuggestionStyle::ShowCode }
-            }
-            SubdiagnosticSuggestionKind::Short => {
-                quote! { rustc_errors::SuggestionStyle::HideCodeInline }
-            }
-            SubdiagnosticSuggestionKind::Hidden => {
-                quote! { rustc_errors::SuggestionStyle::HideCodeAlways }
-            }
-            SubdiagnosticSuggestionKind::Verbose => {
-                quote! { rustc_errors::SuggestionStyle::ShowAlways }
-            }
-        }
-    }
-}
-
-/// Which kind of subdiagnostic is being created from a variant?
-#[derive(Clone)]
-enum SubdiagnosticKind {
-    /// `#[label(...)]`
-    Label,
-    /// `#[note(...)]`
-    Note,
-    /// `#[help(...)]`
-    Help,
-    /// `#[warning(...)]`
-    Warn,
-    /// `#[suggestion{,_short,_hidden,_verbose}]`
-    Suggestion { suggestion_kind: SubdiagnosticSuggestionKind, code: TokenStream },
-    /// `#[multipart_suggestion{,_short,_hidden,_verbose}]`
-    MultipartSuggestion { suggestion_kind: SubdiagnosticSuggestionKind },
-}
-
-impl quote::IdentFragment for SubdiagnosticKind {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            SubdiagnosticKind::Label => write!(f, "label"),
-            SubdiagnosticKind::Note => write!(f, "note"),
-            SubdiagnosticKind::Help => write!(f, "help"),
-            SubdiagnosticKind::Warn => write!(f, "warn"),
-            SubdiagnosticKind::Suggestion { .. } => write!(f, "suggestion_with_style"),
-            SubdiagnosticKind::MultipartSuggestion { .. } => {
-                write!(f, "multipart_suggestion_with_style")
-            }
-        }
-    }
-
-    fn span(&self) -> Option<proc_macro2::Span> {
-        None
-    }
-}
+use super::utils::{SpannedOption, SubdiagnosticKind};
 
 /// The central struct for constructing the `add_to_diagnostic` method from an annotated struct.
 pub(crate) struct SubdiagnosticDerive<'a> {
@@ -198,8 +114,8 @@ struct SubdiagnosticDeriveBuilder<'a> {
 
     /// Identifier for the binding to the `#[primary_span]` field.
     span_field: SpannedOption<proc_macro2::Ident>,
-    /// If a suggestion, the identifier for the binding to the `#[applicability]` field or a
-    /// `rustc_errors::Applicability::*` variant directly.
+
+    /// The binding to the `#[applicability]` field, if present.
     applicability: SpannedOption<TokenStream>,
 
     /// Set to true when a `#[suggestion_part]` field is encountered, used to generate an error
@@ -219,6 +135,7 @@ struct KindsStatistics {
     has_multipart_suggestion: bool,
     all_multipart_suggestions: bool,
     has_normal_suggestion: bool,
+    all_applicabilities_static: bool,
 }
 
 impl<'a> FromIterator<&'a SubdiagnosticKind> for KindsStatistics {
@@ -227,8 +144,15 @@ impl<'a> FromIterator<&'a SubdiagnosticKind> for KindsStatistics {
             has_multipart_suggestion: false,
             all_multipart_suggestions: true,
             has_normal_suggestion: false,
+            all_applicabilities_static: true,
         };
+
         for kind in kinds {
+            if let SubdiagnosticKind::MultipartSuggestion { applicability: None, .. }
+            | SubdiagnosticKind::Suggestion { applicability: None, .. } = kind
+            {
+                ret.all_applicabilities_static = false;
+            }
             if let SubdiagnosticKind::MultipartSuggestion { .. } = kind {
                 ret.has_multipart_suggestion = true;
             } else {
@@ -248,129 +172,14 @@ impl<'a> SubdiagnosticDeriveBuilder<'a> {
         let mut kind_slugs = vec![];
 
         for attr in self.variant.ast().attrs {
-            let span = attr.span().unwrap();
-
-            let name = attr.path.segments.last().unwrap().ident.to_string();
-            let name = name.as_str();
-
-            let meta = attr.parse_meta()?;
-            let Meta::List(MetaList { ref nested, .. }) = meta else {
-                throw_invalid_attr!(attr, &meta);
-            };
-
-            let mut kind = match name {
-                "label" => SubdiagnosticKind::Label,
-                "note" => SubdiagnosticKind::Note,
-                "help" => SubdiagnosticKind::Help,
-                "warning" => SubdiagnosticKind::Warn,
-                _ => {
-                    if let Some(suggestion_kind) =
-                        name.strip_prefix("suggestion").and_then(|s| s.parse().ok())
-                    {
-                        SubdiagnosticKind::Suggestion { suggestion_kind, code: TokenStream::new() }
-                    } else if let Some(suggestion_kind) =
-                        name.strip_prefix("multipart_suggestion").and_then(|s| s.parse().ok())
-                    {
-                        SubdiagnosticKind::MultipartSuggestion { suggestion_kind }
-                    } else {
-                        throw_invalid_attr!(attr, &meta);
-                    }
-                }
-            };
-
-            let mut slug = None;
-            let mut code = None;
-
-            let mut nested_iter = nested.into_iter();
-            if let Some(nested_attr) = nested_iter.next() {
-                match nested_attr {
-                    NestedMeta::Meta(Meta::Path(path)) => {
-                        slug.set_once(path.clone(), span);
-                    }
-                    NestedMeta::Meta(meta @ Meta::NameValue(_))
-                        if matches!(
-                            meta.path().segments.last().unwrap().ident.to_string().as_str(),
-                            "code" | "applicability"
-                        ) =>
-                    {
-                        // Don't error for valid follow-up attributes.
-                    }
-                    nested_attr => {
-                        throw_invalid_nested_attr!(attr, &nested_attr, |diag| {
-                            diag.help(
-                                "first argument of the attribute should be the diagnostic \
-                                 slug",
-                            )
-                        })
-                    }
-                };
-            }
+            let (kind, slug) = SubdiagnosticKind::from_attr(attr, self)?;
 
-            for nested_attr in nested_iter {
-                let meta = match nested_attr {
-                    NestedMeta::Meta(ref meta) => meta,
-                    _ => throw_invalid_nested_attr!(attr, &nested_attr),
-                };
-
-                let span = meta.span().unwrap();
-                let nested_name = meta.path().segments.last().unwrap().ident.to_string();
-                let nested_name = nested_name.as_str();
-
-                let value = match meta {
-                    Meta::NameValue(MetaNameValue { lit: syn::Lit::Str(value), .. }) => value,
-                    Meta::Path(_) => throw_invalid_nested_attr!(attr, &nested_attr, |diag| {
-                        diag.help("a diagnostic slug must be the first argument to the attribute")
-                    }),
-                    _ => throw_invalid_nested_attr!(attr, &nested_attr),
-                };
-
-                match nested_name {
-                    "code" => {
-                        if matches!(kind, SubdiagnosticKind::Suggestion { .. }) {
-                            let formatted_str = self.build_format(&value.value(), value.span());
-                            code.set_once(formatted_str, span);
-                        } else {
-                            span_err(
-                                span,
-                                &format!(
-                                    "`code` is not a valid nested attribute of a `{}` attribute",
-                                    name
-                                ),
-                            )
-                            .emit();
-                        }
-                    }
-                    "applicability" => {
-                        if matches!(
-                            kind,
-                            SubdiagnosticKind::Suggestion { .. }
-                                | SubdiagnosticKind::MultipartSuggestion { .. }
-                        ) {
-                            let value =
-                                Applicability::from_str(&value.value()).unwrap_or_else(|()| {
-                                    span_err(span, "invalid applicability").emit();
-                                    Applicability::Unspecified
-                                });
-                            self.applicability.set_once(quote! { #value }, span);
-                        } else {
-                            span_err(
-                                span,
-                                &format!(
-                                    "`applicability` is not a valid nested attribute of a `{}` attribute",
-                                    name
-                                )
-                            ).emit();
-                        }
-                    }
-                    _ => throw_invalid_nested_attr!(attr, &nested_attr, |diag| {
-                        diag.help("only `code` and `applicability` are valid nested attributes")
-                    }),
-                }
-            }
+            let Some(slug) = slug else {
+                let name = attr.path.segments.last().unwrap().ident.to_string();
+                let name = name.as_str();
 
-            let Some((slug, _)) = slug else {
                 throw_span_err!(
-                    span,
+                    attr.span().unwrap(),
                     &format!(
                         "diagnostic slug must be first argument of a `#[{}(...)]` attribute",
                         name
@@ -378,21 +187,7 @@ impl<'a> SubdiagnosticDeriveBuilder<'a> {
                 );
             };
 
-            match kind {
-                SubdiagnosticKind::Suggestion { code: ref mut code_field, .. } => {
-                    let Some((code, _)) = code else {
-                        throw_span_err!(span, "suggestion without `code = \"...\"`");
-                    };
-                    *code_field = code;
-                }
-                SubdiagnosticKind::Label
-                | SubdiagnosticKind::Note
-                | SubdiagnosticKind::Help
-                | SubdiagnosticKind::Warn
-                | SubdiagnosticKind::MultipartSuggestion { .. } => {}
-            }
-
-            kind_slugs.push((kind, slug))
+            kind_slugs.push((kind, slug));
         }
 
         Ok(kind_slugs)
@@ -510,6 +305,15 @@ impl<'a> SubdiagnosticDeriveBuilder<'a> {
                 if kind_stats.has_multipart_suggestion || kind_stats.has_normal_suggestion {
                     report_error_if_not_applied_to_applicability(attr, &info)?;
 
+                    if kind_stats.all_applicabilities_static {
+                        span_err(
+                            span,
+                            "`#[applicability]` has no effect if all `#[suggestion]`/\
+                             `#[multipart_suggestion]` attributes have a static \
+                             `applicability = \"...\"`",
+                        )
+                        .emit();
+                    }
                     let binding = info.binding.binding.clone();
                     self.applicability.set_once(quote! { #binding }, span);
                 } else {
@@ -638,11 +442,6 @@ impl<'a> SubdiagnosticDeriveBuilder<'a> {
             .collect();
 
         let span_field = self.span_field.value_ref();
-        let applicability = self
-            .applicability
-            .take()
-            .value()
-            .unwrap_or_else(|| quote! { rustc_errors::Applicability::Unspecified });
 
         let diag = &self.diag;
         let mut calls = TokenStream::new();
@@ -650,7 +449,13 @@ impl<'a> SubdiagnosticDeriveBuilder<'a> {
             let name = format_ident!("{}{}", if span_field.is_some() { "span_" } else { "" }, kind);
             let message = quote! { rustc_errors::fluent::#slug };
             let call = match kind {
-                SubdiagnosticKind::Suggestion { suggestion_kind, code } => {
+                SubdiagnosticKind::Suggestion { suggestion_kind, applicability, code } => {
+                    let applicability = applicability
+                        .value()
+                        .map(|a| quote! { #a })
+                        .or_else(|| self.applicability.take().value())
+                        .unwrap_or_else(|| quote! { rustc_errors::Applicability::Unspecified });
+
                     if let Some(span) = span_field {
                         let style = suggestion_kind.to_suggestion_style();
 
@@ -660,7 +465,13 @@ impl<'a> SubdiagnosticDeriveBuilder<'a> {
                         quote! { unreachable!(); }
                     }
                 }
-                SubdiagnosticKind::MultipartSuggestion { suggestion_kind } => {
+                SubdiagnosticKind::MultipartSuggestion { suggestion_kind, applicability } => {
+                    let applicability = applicability
+                        .value()
+                        .map(|a| quote! { #a })
+                        .or_else(|| self.applicability.take().value())
+                        .unwrap_or_else(|| quote! { rustc_errors::Applicability::Unspecified });
+
                     if !self.has_suggestion_parts {
                         span_err(
                             self.span,
diff --git a/compiler/rustc_macros/src/diagnostics/utils.rs b/compiler/rustc_macros/src/diagnostics/utils.rs
index 3efcd216d19..a31bda9ca0d 100644
--- a/compiler/rustc_macros/src/diagnostics/utils.rs
+++ b/compiler/rustc_macros/src/diagnostics/utils.rs
@@ -1,12 +1,18 @@
-use crate::diagnostics::error::{span_err, throw_span_err, DiagnosticDeriveError};
+use crate::diagnostics::error::{
+    span_err, throw_invalid_attr, throw_invalid_nested_attr, throw_span_err, DiagnosticDeriveError,
+};
 use proc_macro::Span;
 use proc_macro2::TokenStream;
 use quote::{format_ident, quote, ToTokens};
 use std::collections::{BTreeSet, HashMap};
+use std::fmt;
 use std::str::FromStr;
 use syn::{spanned::Spanned, Attribute, Meta, Type, TypeTuple};
+use syn::{MetaList, MetaNameValue, NestedMeta, Path};
 use synstructure::{BindingInfo, Structure};
 
+use super::error::invalid_nested_attr;
+
 /// Checks whether the type name of `ty` matches `name`.
 ///
 /// Given some struct at `a::b::c::Foo`, this will return true for `c::Foo`, `b::c::Foo`, or
@@ -311,6 +317,7 @@ pub(crate) trait HasFieldMap {
 
 /// `Applicability` of a suggestion - mirrors `rustc_errors::Applicability` - and used to represent
 /// the user's selection of applicability if specified in an attribute.
+#[derive(Clone, Copy)]
 pub(crate) enum Applicability {
     MachineApplicable,
     MaybeIncorrect,
@@ -367,3 +374,250 @@ pub(crate) fn build_field_mapping<'a>(structure: &Structure<'a>) -> HashMap<Stri
 
     fields_map
 }
+
+/// Possible styles for suggestion subdiagnostics.
+#[derive(Clone, Copy)]
+pub(super) enum SuggestionKind {
+    /// `#[suggestion]`
+    Normal,
+    /// `#[suggestion_short]`
+    Short,
+    /// `#[suggestion_hidden]`
+    Hidden,
+    /// `#[suggestion_verbose]`
+    Verbose,
+}
+
+impl FromStr for SuggestionKind {
+    type Err = ();
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "" => Ok(SuggestionKind::Normal),
+            "_short" => Ok(SuggestionKind::Short),
+            "_hidden" => Ok(SuggestionKind::Hidden),
+            "_verbose" => Ok(SuggestionKind::Verbose),
+            _ => Err(()),
+        }
+    }
+}
+
+impl SuggestionKind {
+    pub fn to_suggestion_style(&self) -> TokenStream {
+        match self {
+            SuggestionKind::Normal => {
+                quote! { rustc_errors::SuggestionStyle::ShowCode }
+            }
+            SuggestionKind::Short => {
+                quote! { rustc_errors::SuggestionStyle::HideCodeInline }
+            }
+            SuggestionKind::Hidden => {
+                quote! { rustc_errors::SuggestionStyle::HideCodeAlways }
+            }
+            SuggestionKind::Verbose => {
+                quote! { rustc_errors::SuggestionStyle::ShowAlways }
+            }
+        }
+    }
+}
+
+/// Types of subdiagnostics that can be created using attributes
+#[derive(Clone)]
+pub(super) enum SubdiagnosticKind {
+    /// `#[label(...)]`
+    Label,
+    /// `#[note(...)]`
+    Note,
+    /// `#[help(...)]`
+    Help,
+    /// `#[warning(...)]`
+    Warn,
+    /// `#[suggestion{,_short,_hidden,_verbose}]`
+    Suggestion {
+        suggestion_kind: SuggestionKind,
+        applicability: SpannedOption<Applicability>,
+        code: TokenStream,
+    },
+    /// `#[multipart_suggestion{,_short,_hidden,_verbose}]`
+    MultipartSuggestion {
+        suggestion_kind: SuggestionKind,
+        applicability: SpannedOption<Applicability>,
+    },
+}
+
+impl SubdiagnosticKind {
+    /// Constructs a `SubdiagnosticKind` from a field or type attribute such as `#[note]`,
+    /// `#[error(parser::add_paren)]` or `#[suggestion(code = "...")]`. Returns the
+    /// `SubdiagnosticKind` and the diagnostic slug, if specified.
+    pub(super) fn from_attr(
+        attr: &Attribute,
+        fields: &impl HasFieldMap,
+    ) -> Result<(SubdiagnosticKind, Option<Path>), DiagnosticDeriveError> {
+        let span = attr.span().unwrap();
+
+        let name = attr.path.segments.last().unwrap().ident.to_string();
+        let name = name.as_str();
+
+        let meta = attr.parse_meta()?;
+        let mut kind = match name {
+            "label" => SubdiagnosticKind::Label,
+            "note" => SubdiagnosticKind::Note,
+            "help" => SubdiagnosticKind::Help,
+            "warning" => SubdiagnosticKind::Warn,
+            _ => {
+                if let Some(suggestion_kind) =
+                    name.strip_prefix("suggestion").and_then(|s| s.parse().ok())
+                {
+                    SubdiagnosticKind::Suggestion {
+                        suggestion_kind,
+                        applicability: None,
+                        code: TokenStream::new(),
+                    }
+                } else if let Some(suggestion_kind) =
+                    name.strip_prefix("multipart_suggestion").and_then(|s| s.parse().ok())
+                {
+                    SubdiagnosticKind::MultipartSuggestion { suggestion_kind, applicability: None }
+                } else {
+                    throw_invalid_attr!(attr, &meta);
+                }
+            }
+        };
+
+        let nested = match meta {
+            Meta::List(MetaList { ref nested, .. }) => {
+                // An attribute with properties, such as `#[suggestion(code = "...")]` or
+                // `#[error(some::slug)]`
+                nested
+            }
+            Meta::Path(_) => {
+                // An attribute without a slug or other properties, such as `#[note]` - return
+                // without further processing.
+                //
+                // Only allow this if there are no mandatory properties, such as `code = "..."` in
+                // `#[suggestion(...)]`
+                match kind {
+                    SubdiagnosticKind::Label
+                    | SubdiagnosticKind::Note
+                    | SubdiagnosticKind::Help
+                    | SubdiagnosticKind::Warn
+                    | SubdiagnosticKind::MultipartSuggestion { .. } => return Ok((kind, None)),
+                    SubdiagnosticKind::Suggestion { .. } => {
+                        throw_span_err!(span, "suggestion without `code = \"...\"`")
+                    }
+                }
+            }
+            _ => {
+                throw_invalid_attr!(attr, &meta)
+            }
+        };
+
+        let mut code = None;
+
+        let mut nested_iter = nested.into_iter().peekable();
+
+        // Peek at the first nested attribute: if it's a slug path, consume it.
+        let slug = if let Some(NestedMeta::Meta(Meta::Path(path))) = nested_iter.peek() {
+            let path = path.clone();
+            // Advance the iterator.
+            nested_iter.next();
+            Some(path)
+        } else {
+            None
+        };
+
+        for nested_attr in nested_iter {
+            let meta = match nested_attr {
+                NestedMeta::Meta(ref meta) => meta,
+                NestedMeta::Lit(_) => {
+                    invalid_nested_attr(attr, &nested_attr).emit();
+                    continue;
+                }
+            };
+
+            let span = meta.span().unwrap();
+            let nested_name = meta.path().segments.last().unwrap().ident.to_string();
+            let nested_name = nested_name.as_str();
+
+            let value = match meta {
+                Meta::NameValue(MetaNameValue { lit: syn::Lit::Str(value), .. }) => value,
+                Meta::Path(_) => throw_invalid_nested_attr!(attr, &nested_attr, |diag| {
+                    diag.help("a diagnostic slug must be the first argument to the attribute")
+                }),
+                _ => {
+                    invalid_nested_attr(attr, &nested_attr).emit();
+                    continue;
+                }
+            };
+
+            match (nested_name, &mut kind) {
+                ("code", SubdiagnosticKind::Suggestion { .. }) => {
+                    let formatted_str = fields.build_format(&value.value(), value.span());
+                    code.set_once(formatted_str, span);
+                }
+                (
+                    "applicability",
+                    SubdiagnosticKind::Suggestion { ref mut applicability, .. }
+                    | SubdiagnosticKind::MultipartSuggestion { ref mut applicability, .. },
+                ) => {
+                    let value = Applicability::from_str(&value.value()).unwrap_or_else(|()| {
+                        span_err(span, "invalid applicability").emit();
+                        Applicability::Unspecified
+                    });
+                    applicability.set_once(value, span);
+                }
+
+                // Invalid nested attribute
+                (_, SubdiagnosticKind::Suggestion { .. }) => {
+                    invalid_nested_attr(attr, &nested_attr)
+                        .help("only `code` and `applicability` are valid nested attributes")
+                        .emit();
+                }
+                (_, SubdiagnosticKind::MultipartSuggestion { .. }) => {
+                    invalid_nested_attr(attr, &nested_attr)
+                        .help("only `applicability` is a valid nested attributes")
+                        .emit()
+                }
+                _ => {
+                    invalid_nested_attr(attr, &nested_attr).emit();
+                }
+            }
+        }
+
+        match kind {
+            SubdiagnosticKind::Suggestion { code: ref mut code_field, .. } => {
+                *code_field = if let Some((code, _)) = code {
+                    code
+                } else {
+                    span_err(span, "suggestion without `code = \"...\"`").emit();
+                    quote! { "" }
+                }
+            }
+            SubdiagnosticKind::Label
+            | SubdiagnosticKind::Note
+            | SubdiagnosticKind::Help
+            | SubdiagnosticKind::Warn
+            | SubdiagnosticKind::MultipartSuggestion { .. } => {}
+        }
+
+        Ok((kind, slug))
+    }
+}
+
+impl quote::IdentFragment for SubdiagnosticKind {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            SubdiagnosticKind::Label => write!(f, "label"),
+            SubdiagnosticKind::Note => write!(f, "note"),
+            SubdiagnosticKind::Help => write!(f, "help"),
+            SubdiagnosticKind::Warn => write!(f, "warn"),
+            SubdiagnosticKind::Suggestion { .. } => write!(f, "suggestion_with_style"),
+            SubdiagnosticKind::MultipartSuggestion { .. } => {
+                write!(f, "multipart_suggestion_with_style")
+            }
+        }
+    }
+
+    fn span(&self) -> Option<proc_macro2::Span> {
+        None
+    }
+}
diff --git a/src/test/ui-fulldeps/session-diagnostic/subdiagnostic-derive.rs b/src/test/ui-fulldeps/session-diagnostic/subdiagnostic-derive.rs
index 9fbe7b1f4c8..606b3b5e5eb 100644
--- a/src/test/ui-fulldeps/session-diagnostic/subdiagnostic-derive.rs
+++ b/src/test/ui-fulldeps/session-diagnostic/subdiagnostic-derive.rs
@@ -52,7 +52,7 @@ struct C {
 
 #[derive(Subdiagnostic)]
 #[label]
-//~^ ERROR `#[label]` is not a valid attribute
+//~^ ERROR diagnostic slug must be first argument
 struct D {
     #[primary_span]
     span: Span,
@@ -81,6 +81,7 @@ struct F {
 #[derive(Subdiagnostic)]
 #[label(bug = "...")]
 //~^ ERROR `#[label(bug = ...)]` is not a valid attribute
+//~| ERROR diagnostic slug must be first argument
 struct G {
     #[primary_span]
     span: Span,
@@ -90,6 +91,7 @@ struct G {
 #[derive(Subdiagnostic)]
 #[label("...")]
 //~^ ERROR `#[label("...")]` is not a valid attribute
+//~| ERROR diagnostic slug must be first argument
 struct H {
     #[primary_span]
     span: Span,
@@ -99,6 +101,7 @@ struct H {
 #[derive(Subdiagnostic)]
 #[label(slug = 4)]
 //~^ ERROR `#[label(slug = ...)]` is not a valid attribute
+//~| ERROR diagnostic slug must be first argument
 struct J {
     #[primary_span]
     span: Span,
@@ -108,6 +111,7 @@ struct J {
 #[derive(Subdiagnostic)]
 #[label(slug("..."))]
 //~^ ERROR `#[label(slug(...))]` is not a valid attribute
+//~| ERROR diagnostic slug must be first argument
 struct K {
     #[primary_span]
     span: Span,
@@ -135,7 +139,7 @@ struct M {
 
 #[derive(Subdiagnostic)]
 #[label(parser::add_paren, code = "...")]
-//~^ ERROR `code` is not a valid nested attribute of a `label` attribute
+//~^ ERROR `#[label(code = ...)]` is not a valid attribute
 struct N {
     #[primary_span]
     span: Span,
@@ -144,7 +148,7 @@ struct N {
 
 #[derive(Subdiagnostic)]
 #[label(parser::add_paren, applicability = "machine-applicable")]
-//~^ ERROR `applicability` is not a valid nested attribute of a `label` attribute
+//~^ ERROR `#[label(applicability = ...)]` is not a valid attribute
 struct O {
     #[primary_span]
     span: Span,
@@ -216,6 +220,7 @@ enum T {
 enum U {
     #[label(code = "...")]
     //~^ ERROR diagnostic slug must be first argument of a `#[label(...)]` attribute
+    //~| ERROR `#[label(code = ...)]` is not a valid attribute
     A {
         #[primary_span]
         span: Span,
@@ -531,7 +536,7 @@ struct BA {
 #[derive(Subdiagnostic)]
 #[multipart_suggestion(parser::add_paren, code = "...", applicability = "machine-applicable")]
 //~^ ERROR multipart suggestion without any `#[suggestion_part(...)]` fields
-//~| ERROR `code` is not a valid nested attribute of a `multipart_suggestion` attribute
+//~| ERROR `#[multipart_suggestion(code = ...)]` is not a valid attribute
 struct BBa {
     var: String,
 }
@@ -612,10 +617,9 @@ struct BG {
 
 #[derive(Subdiagnostic)]
 #[multipart_suggestion(parser::add_paren, applicability = "machine-applicable")]
-//~^ NOTE previously specified here
 struct BH {
     #[applicability]
-    //~^ ERROR specified multiple times
+    //~^ ERROR `#[applicability]` has no effect
     appl: Applicability,
     #[suggestion_part(code = "(")]
     first: Span,
diff --git a/src/test/ui-fulldeps/session-diagnostic/subdiagnostic-derive.stderr b/src/test/ui-fulldeps/session-diagnostic/subdiagnostic-derive.stderr
index 0a0247e8980..171b89e657d 100644
--- a/src/test/ui-fulldeps/session-diagnostic/subdiagnostic-derive.stderr
+++ b/src/test/ui-fulldeps/session-diagnostic/subdiagnostic-derive.stderr
@@ -8,7 +8,7 @@ LL | |     var: String,
 LL | | }
    | |_^
 
-error: `#[label]` is not a valid attribute
+error: diagnostic slug must be first argument of a `#[label(...)]` attribute
   --> $DIR/subdiagnostic-derive.rs:54:1
    |
 LL | #[label]
@@ -31,101 +31,123 @@ error: `#[label(bug = ...)]` is not a valid attribute
    |
 LL | #[label(bug = "...")]
    |         ^^^^^^^^^^^
+
+error: diagnostic slug must be first argument of a `#[label(...)]` attribute
+  --> $DIR/subdiagnostic-derive.rs:82:1
    |
-   = help: first argument of the attribute should be the diagnostic slug
+LL | #[label(bug = "...")]
+   | ^^^^^^^^^^^^^^^^^^^^^
 
 error: `#[label("...")]` is not a valid attribute
-  --> $DIR/subdiagnostic-derive.rs:91:9
+  --> $DIR/subdiagnostic-derive.rs:92:9
    |
 LL | #[label("...")]
    |         ^^^^^
+
+error: diagnostic slug must be first argument of a `#[label(...)]` attribute
+  --> $DIR/subdiagnostic-derive.rs:92:1
    |
-   = help: first argument of the attribute should be the diagnostic slug
+LL | #[label("...")]
+   | ^^^^^^^^^^^^^^^
 
 error: `#[label(slug = ...)]` is not a valid attribute
-  --> $DIR/subdiagnostic-derive.rs:100:9
+  --> $DIR/subdiagnostic-derive.rs:102:9
    |
 LL | #[label(slug = 4)]
    |         ^^^^^^^^
+
+error: diagnostic slug must be first argument of a `#[label(...)]` attribute
+  --> $DIR/subdiagnostic-derive.rs:102:1
    |
-   = help: first argument of the attribute should be the diagnostic slug
+LL | #[label(slug = 4)]
+   | ^^^^^^^^^^^^^^^^^^
 
 error: `#[label(slug(...))]` is not a valid attribute
-  --> $DIR/subdiagnostic-derive.rs:109:9
+  --> $DIR/subdiagnostic-derive.rs:112:9
    |
 LL | #[label(slug("..."))]
    |         ^^^^^^^^^^^
+
+error: diagnostic slug must be first argument of a `#[label(...)]` attribute
+  --> $DIR/subdiagnostic-derive.rs:112:1
    |
-   = help: first argument of the attribute should be the diagnostic slug
+LL | #[label(slug("..."))]
+   | ^^^^^^^^^^^^^^^^^^^^^
 
 error: diagnostic slug must be first argument of a `#[label(...)]` attribute
-  --> $DIR/subdiagnostic-derive.rs:128:1
+  --> $DIR/subdiagnostic-derive.rs:132:1
    |
 LL | #[label()]
    | ^^^^^^^^^^
 
-error: `code` is not a valid nested attribute of a `label` attribute
-  --> $DIR/subdiagnostic-derive.rs:137:28
+error: `#[label(code = ...)]` is not a valid attribute
+  --> $DIR/subdiagnostic-derive.rs:141:28
    |
 LL | #[label(parser::add_paren, code = "...")]
    |                            ^^^^^^^^^^^^
 
-error: `applicability` is not a valid nested attribute of a `label` attribute
-  --> $DIR/subdiagnostic-derive.rs:146:28
+error: `#[label(applicability = ...)]` is not a valid attribute
+  --> $DIR/subdiagnostic-derive.rs:150:28
    |
 LL | #[label(parser::add_paren, applicability = "machine-applicable")]
    |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: unsupported type attribute for subdiagnostic enum
-  --> $DIR/subdiagnostic-derive.rs:155:1
+  --> $DIR/subdiagnostic-derive.rs:159:1
    |
 LL | #[foo]
    | ^^^^^^
 
 error: `#[bar]` is not a valid attribute
-  --> $DIR/subdiagnostic-derive.rs:169:5
+  --> $DIR/subdiagnostic-derive.rs:173:5
    |
 LL |     #[bar]
    |     ^^^^^^
 
 error: `#[bar = ...]` is not a valid attribute
-  --> $DIR/subdiagnostic-derive.rs:181:5
+  --> $DIR/subdiagnostic-derive.rs:185:5
    |
 LL |     #[bar = "..."]
    |     ^^^^^^^^^^^^^^
 
 error: `#[bar = ...]` is not a valid attribute
-  --> $DIR/subdiagnostic-derive.rs:193:5
+  --> $DIR/subdiagnostic-derive.rs:197:5
    |
 LL |     #[bar = 4]
    |     ^^^^^^^^^^
 
 error: `#[bar(...)]` is not a valid attribute
-  --> $DIR/subdiagnostic-derive.rs:205:5
+  --> $DIR/subdiagnostic-derive.rs:209:5
    |
 LL |     #[bar("...")]
    |     ^^^^^^^^^^^^^
 
+error: `#[label(code = ...)]` is not a valid attribute
+  --> $DIR/subdiagnostic-derive.rs:221:13
+   |
+LL |     #[label(code = "...")]
+   |             ^^^^^^^^^^^^
+
 error: diagnostic slug must be first argument of a `#[label(...)]` attribute
-  --> $DIR/subdiagnostic-derive.rs:217:5
+  --> $DIR/subdiagnostic-derive.rs:221:5
    |
 LL |     #[label(code = "...")]
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 error: subdiagnostic kind not specified
-  --> $DIR/subdiagnostic-derive.rs:234:5
+  --> $DIR/subdiagnostic-derive.rs:239:5
    |
 LL |     B {
    |     ^
 
 error: the `#[primary_span]` attribute can only be applied to fields of type `Span` or `MultiSpan`
-  --> $DIR/subdiagnostic-derive.rs:246:5
+  --> $DIR/subdiagnostic-derive.rs:251:5
    |
 LL |     #[primary_span]
    |     ^^^^^^^^^^^^^^^
 
 error: label without `#[primary_span]` field
-  --> $DIR/subdiagnostic-derive.rs:243:1
+  --> $DIR/subdiagnostic-derive.rs:248:1
    |
 LL | / #[label(parser::add_paren)]
 LL | |
@@ -137,13 +159,13 @@ LL | | }
    | |_^
 
 error: `#[applicability]` is only valid on suggestions
-  --> $DIR/subdiagnostic-derive.rs:256:5
+  --> $DIR/subdiagnostic-derive.rs:261:5
    |
 LL |     #[applicability]
    |     ^^^^^^^^^^^^^^^^
 
 error: `#[bar]` is not a valid attribute
-  --> $DIR/subdiagnostic-derive.rs:266:5
+  --> $DIR/subdiagnostic-derive.rs:271:5
    |
 LL |     #[bar]
    |     ^^^^^^
@@ -151,13 +173,13 @@ LL |     #[bar]
    = help: only `primary_span`, `applicability` and `skip_arg` are valid field attributes
 
 error: `#[bar = ...]` is not a valid attribute
-  --> $DIR/subdiagnostic-derive.rs:277:5
+  --> $DIR/subdiagnostic-derive.rs:282:5
    |
 LL |     #[bar = "..."]
    |     ^^^^^^^^^^^^^^
 
 error: `#[bar(...)]` is not a valid attribute
-  --> $DIR/subdiagnostic-derive.rs:288:5
+  --> $DIR/subdiagnostic-derive.rs:293:5
    |
 LL |     #[bar("...")]
    |     ^^^^^^^^^^^^^
@@ -165,7 +187,7 @@ LL |     #[bar("...")]
    = help: only `primary_span`, `applicability` and `skip_arg` are valid field attributes
 
 error: unexpected unsupported untagged union
-  --> $DIR/subdiagnostic-derive.rs:304:1
+  --> $DIR/subdiagnostic-derive.rs:309:1
    |
 LL | / union AC {
 LL | |
@@ -175,7 +197,7 @@ LL | | }
    | |_^
 
 error: `#[label(parser::add_paren)]` is not a valid attribute
-  --> $DIR/subdiagnostic-derive.rs:319:28
+  --> $DIR/subdiagnostic-derive.rs:324:28
    |
 LL | #[label(parser::add_paren, parser::add_paren)]
    |                            ^^^^^^^^^^^^^^^^^
@@ -183,67 +205,67 @@ LL | #[label(parser::add_paren, parser::add_paren)]
    = help: a diagnostic slug must be the first argument to the attribute
 
 error: specified multiple times
-  --> $DIR/subdiagnostic-derive.rs:332:5
+  --> $DIR/subdiagnostic-derive.rs:337:5
    |
 LL |     #[primary_span]
    |     ^^^^^^^^^^^^^^^
    |
 note: previously specified here
-  --> $DIR/subdiagnostic-derive.rs:329:5
+  --> $DIR/subdiagnostic-derive.rs:334:5
    |
 LL |     #[primary_span]
    |     ^^^^^^^^^^^^^^^
 
 error: subdiagnostic kind not specified
-  --> $DIR/subdiagnostic-derive.rs:338:8
+  --> $DIR/subdiagnostic-derive.rs:343:8
    |
 LL | struct AG {
    |        ^^
 
 error: specified multiple times
-  --> $DIR/subdiagnostic-derive.rs:375:47
+  --> $DIR/subdiagnostic-derive.rs:380:47
    |
 LL | #[suggestion(parser::add_paren, code = "...", code = "...")]
    |                                               ^^^^^^^^^^^^
    |
 note: previously specified here
-  --> $DIR/subdiagnostic-derive.rs:375:33
+  --> $DIR/subdiagnostic-derive.rs:380:33
    |
 LL | #[suggestion(parser::add_paren, code = "...", code = "...")]
    |                                 ^^^^^^^^^^^^
 
 error: specified multiple times
-  --> $DIR/subdiagnostic-derive.rs:393:5
+  --> $DIR/subdiagnostic-derive.rs:398:5
    |
 LL |     #[applicability]
    |     ^^^^^^^^^^^^^^^^
    |
 note: previously specified here
-  --> $DIR/subdiagnostic-derive.rs:390:5
+  --> $DIR/subdiagnostic-derive.rs:395:5
    |
 LL |     #[applicability]
    |     ^^^^^^^^^^^^^^^^
 
 error: the `#[applicability]` attribute can only be applied to fields of type `Applicability`
-  --> $DIR/subdiagnostic-derive.rs:403:5
+  --> $DIR/subdiagnostic-derive.rs:408:5
    |
 LL |     #[applicability]
    |     ^^^^^^^^^^^^^^^^
 
 error: suggestion without `code = "..."`
-  --> $DIR/subdiagnostic-derive.rs:416:1
+  --> $DIR/subdiagnostic-derive.rs:421:1
    |
 LL | #[suggestion(parser::add_paren)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: invalid applicability
-  --> $DIR/subdiagnostic-derive.rs:426:46
+  --> $DIR/subdiagnostic-derive.rs:431:46
    |
 LL | #[suggestion(parser::add_paren, code ="...", applicability = "foo")]
    |                                              ^^^^^^^^^^^^^^^^^^^^^
 
 error: suggestion without `#[primary_span]` field
-  --> $DIR/subdiagnostic-derive.rs:444:1
+  --> $DIR/subdiagnostic-derive.rs:449:1
    |
 LL | / #[suggestion(parser::add_paren, code = "...")]
 LL | |
@@ -253,25 +275,25 @@ LL | | }
    | |_^
 
 error: unsupported type attribute for subdiagnostic enum
-  --> $DIR/subdiagnostic-derive.rs:458:1
+  --> $DIR/subdiagnostic-derive.rs:463:1
    |
 LL | #[label]
    | ^^^^^^^^
 
 error: `var` doesn't refer to a field on this type
-  --> $DIR/subdiagnostic-derive.rs:478:39
+  --> $DIR/subdiagnostic-derive.rs:483:39
    |
 LL | #[suggestion(parser::add_paren, code ="{var}", applicability = "machine-applicable")]
    |                                       ^^^^^^^
 
 error: `var` doesn't refer to a field on this type
-  --> $DIR/subdiagnostic-derive.rs:497:43
+  --> $DIR/subdiagnostic-derive.rs:502:43
    |
 LL |     #[suggestion(parser::add_paren, code ="{var}", applicability = "machine-applicable")]
    |                                           ^^^^^^^
 
 error: `#[suggestion_part]` is not a valid attribute
-  --> $DIR/subdiagnostic-derive.rs:520:5
+  --> $DIR/subdiagnostic-derive.rs:525:5
    |
 LL |     #[suggestion_part]
    |     ^^^^^^^^^^^^^^^^^^
@@ -279,7 +301,7 @@ LL |     #[suggestion_part]
    = help: `#[suggestion_part(...)]` is only valid in multipart suggestions, use `#[primary_span]` instead
 
 error: `#[suggestion_part(...)]` is not a valid attribute
-  --> $DIR/subdiagnostic-derive.rs:523:5
+  --> $DIR/subdiagnostic-derive.rs:528:5
    |
 LL |     #[suggestion_part(code = "...")]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -287,7 +309,7 @@ LL |     #[suggestion_part(code = "...")]
    = help: `#[suggestion_part(...)]` is only valid in multipart suggestions
 
 error: suggestion without `#[primary_span]` field
-  --> $DIR/subdiagnostic-derive.rs:517:1
+  --> $DIR/subdiagnostic-derive.rs:522:1
    |
 LL | / #[suggestion(parser::add_paren, code = "...")]
 LL | |
@@ -298,14 +320,16 @@ LL | |     var: String,
 LL | | }
    | |_^
 
-error: `code` is not a valid nested attribute of a `multipart_suggestion` attribute
-  --> $DIR/subdiagnostic-derive.rs:532:43
+error: `#[multipart_suggestion(code = ...)]` is not a valid attribute
+  --> $DIR/subdiagnostic-derive.rs:537:43
    |
 LL | #[multipart_suggestion(parser::add_paren, code = "...", applicability = "machine-applicable")]
    |                                           ^^^^^^^^^^^^
+   |
+   = help: only `applicability` is a valid nested attributes
 
 error: multipart suggestion without any `#[suggestion_part(...)]` fields
-  --> $DIR/subdiagnostic-derive.rs:532:1
+  --> $DIR/subdiagnostic-derive.rs:537:1
    |
 LL | / #[multipart_suggestion(parser::add_paren, code = "...", applicability = "machine-applicable")]
 LL | |
@@ -316,19 +340,19 @@ LL | | }
    | |_^
 
 error: `#[suggestion_part(...)]` attribute without `code = "..."`
-  --> $DIR/subdiagnostic-derive.rs:542:5
+  --> $DIR/subdiagnostic-derive.rs:547:5
    |
 LL |     #[suggestion_part]
    |     ^^^^^^^^^^^^^^^^^^
 
 error: `#[suggestion_part(...)]` attribute without `code = "..."`
-  --> $DIR/subdiagnostic-derive.rs:550:5
+  --> $DIR/subdiagnostic-derive.rs:555:5
    |
 LL |     #[suggestion_part()]
    |     ^^^^^^^^^^^^^^^^^^^^
 
 error: `#[primary_span]` is not a valid attribute
-  --> $DIR/subdiagnostic-derive.rs:559:5
+  --> $DIR/subdiagnostic-derive.rs:564:5
    |
 LL |     #[primary_span]
    |     ^^^^^^^^^^^^^^^
@@ -336,7 +360,7 @@ LL |     #[primary_span]
    = help: multipart suggestions use one or more `#[suggestion_part]`s rather than one `#[primary_span]`
 
 error: multipart suggestion without any `#[suggestion_part(...)]` fields
-  --> $DIR/subdiagnostic-derive.rs:556:1
+  --> $DIR/subdiagnostic-derive.rs:561:1
    |
 LL | / #[multipart_suggestion(parser::add_paren)]
 LL | |
@@ -348,19 +372,19 @@ LL | | }
    | |_^
 
 error: `#[suggestion_part(...)]` attribute without `code = "..."`
-  --> $DIR/subdiagnostic-derive.rs:567:5
+  --> $DIR/subdiagnostic-derive.rs:572:5
    |
 LL |     #[suggestion_part]
    |     ^^^^^^^^^^^^^^^^^^
 
 error: `#[suggestion_part(...)]` attribute without `code = "..."`
-  --> $DIR/subdiagnostic-derive.rs:570:5
+  --> $DIR/subdiagnostic-derive.rs:575:5
    |
 LL |     #[suggestion_part()]
    |     ^^^^^^^^^^^^^^^^^^^^
 
 error: `#[suggestion_part(foo = ...)]` is not a valid attribute
-  --> $DIR/subdiagnostic-derive.rs:573:23
+  --> $DIR/subdiagnostic-derive.rs:578:23
    |
 LL |     #[suggestion_part(foo = "bar")]
    |                       ^^^^^^^^^^^
@@ -368,40 +392,34 @@ LL |     #[suggestion_part(foo = "bar")]
    = help: `code` is the only valid nested attribute
 
 error: the `#[suggestion_part(...)]` attribute can only be applied to fields of type `Span` or `MultiSpan`
-  --> $DIR/subdiagnostic-derive.rs:576:5
+  --> $DIR/subdiagnostic-derive.rs:581:5
    |
 LL |     #[suggestion_part(code = "...")]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: the `#[suggestion_part(...)]` attribute can only be applied to fields of type `Span` or `MultiSpan`
-  --> $DIR/subdiagnostic-derive.rs:579:5
+  --> $DIR/subdiagnostic-derive.rs:584:5
    |
 LL |     #[suggestion_part()]
    |     ^^^^^^^^^^^^^^^^^^^^
 
 error: specified multiple times
-  --> $DIR/subdiagnostic-derive.rs:587:37
+  --> $DIR/subdiagnostic-derive.rs:592:37
    |
 LL |     #[suggestion_part(code = "...", code = ",,,")]
    |                                     ^^^^^^^^^^^^
    |
 note: previously specified here
-  --> $DIR/subdiagnostic-derive.rs:587:23
+  --> $DIR/subdiagnostic-derive.rs:592:23
    |
 LL |     #[suggestion_part(code = "...", code = ",,,")]
    |                       ^^^^^^^^^^^^
 
-error: specified multiple times
-  --> $DIR/subdiagnostic-derive.rs:617:5
+error: `#[applicability]` has no effect if all `#[suggestion]`/`#[multipart_suggestion]` attributes have a static `applicability = "..."`
+  --> $DIR/subdiagnostic-derive.rs:621:5
    |
 LL |     #[applicability]
    |     ^^^^^^^^^^^^^^^^
-   |
-note: previously specified here
-  --> $DIR/subdiagnostic-derive.rs:614:43
-   |
-LL | #[multipart_suggestion(parser::add_paren, applicability = "machine-applicable")]
-   |                                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: cannot find attribute `foo` in this scope
   --> $DIR/subdiagnostic-derive.rs:63:3
@@ -410,59 +428,59 @@ LL | #[foo]
    |   ^^^
 
 error: cannot find attribute `foo` in this scope
-  --> $DIR/subdiagnostic-derive.rs:155:3
+  --> $DIR/subdiagnostic-derive.rs:159:3
    |
 LL | #[foo]
    |   ^^^
 
 error: cannot find attribute `bar` in this scope
-  --> $DIR/subdiagnostic-derive.rs:169:7
+  --> $DIR/subdiagnostic-derive.rs:173:7
    |
 LL |     #[bar]
    |       ^^^
 
 error: cannot find attribute `bar` in this scope
-  --> $DIR/subdiagnostic-derive.rs:181:7
+  --> $DIR/subdiagnostic-derive.rs:185:7
    |
 LL |     #[bar = "..."]
    |       ^^^
 
 error: cannot find attribute `bar` in this scope
-  --> $DIR/subdiagnostic-derive.rs:193:7
+  --> $DIR/subdiagnostic-derive.rs:197:7
    |
 LL |     #[bar = 4]
    |       ^^^
 
 error: cannot find attribute `bar` in this scope
-  --> $DIR/subdiagnostic-derive.rs:205:7
+  --> $DIR/subdiagnostic-derive.rs:209:7
    |
 LL |     #[bar("...")]
    |       ^^^
 
 error: cannot find attribute `bar` in this scope
-  --> $DIR/subdiagnostic-derive.rs:266:7
+  --> $DIR/subdiagnostic-derive.rs:271:7
    |
 LL |     #[bar]
    |       ^^^
 
 error: cannot find attribute `bar` in this scope
-  --> $DIR/subdiagnostic-derive.rs:277:7
+  --> $DIR/subdiagnostic-derive.rs:282:7
    |
 LL |     #[bar = "..."]
    |       ^^^
 
 error: cannot find attribute `bar` in this scope
-  --> $DIR/subdiagnostic-derive.rs:288:7
+  --> $DIR/subdiagnostic-derive.rs:293:7
    |
 LL |     #[bar("...")]
    |       ^^^
 
 error[E0425]: cannot find value `slug` in module `rustc_errors::fluent`
-  --> $DIR/subdiagnostic-derive.rs:118:9
+  --> $DIR/subdiagnostic-derive.rs:122:9
    |
 LL | #[label(slug)]
    |         ^^^^ not found in `rustc_errors::fluent`
 
-error: aborting due to 63 previous errors
+error: aborting due to 68 previous errors
 
 For more information about this error, try `rustc --explain E0425`.