diff --git a/compiler/rustc_macros/src/diagnostics/diagnostic_builder.rs b/compiler/rustc_macros/src/diagnostics/diagnostic_builder.rs
index fb75d87f8d2..9b91627883a 100644
--- a/compiler/rustc_macros/src/diagnostics/diagnostic_builder.rs
+++ b/compiler/rustc_macros/src/diagnostics/diagnostic_builder.rs
@@ -214,10 +214,15 @@ impl<'a> DiagnosticDeriveVariantBuilder<'a> {
                 if path.is_ident("code") {
                     self.code.set_once((), path.span().unwrap());
 
-                    let code = nested.parse::<TokenStream>()?;
+                    let code = nested.parse::<syn::LitStr>()?;
                     tokens.extend(quote! {
                         #diag.code(rustc_errors::DiagnosticId::Error(#code.to_string()));
                     });
+                } else {
+                    span_err(path.span().unwrap(), "unknown argument").note("only the `code` parameter is valid after the slug").emit();
+
+                    // consume the buffer so we don't have syntax errors from syn
+                    let _ = nested.parse::<TokenStream>();
                 }
                 Ok(())
             })?;
diff --git a/compiler/rustc_macros/src/diagnostics/utils.rs b/compiler/rustc_macros/src/diagnostics/utils.rs
index 38292df6d85..bc104941c38 100644
--- a/compiler/rustc_macros/src/diagnostics/utils.rs
+++ b/compiler/rustc_macros/src/diagnostics/utils.rs
@@ -716,6 +716,9 @@ impl SubdiagnosticKind {
                 }
             }
 
+            let mut has_errors = false;
+            let input = nested.input;
+
             match (nested_name, &mut kind) {
                 ("code", SubdiagnosticKind::Suggestion { code_field, .. }) => {
                     let code_init = build_suggestion_code(
@@ -734,6 +737,7 @@ impl SubdiagnosticKind {
                     let value = get_string!();
                     let value = Applicability::from_str(&value.value()).unwrap_or_else(|()| {
                         span_err(value.span().unwrap(), "invalid applicability").emit();
+                        has_errors = true;
                         Applicability::Unspecified
                     });
                     applicability.set_once(value, span);
@@ -749,6 +753,7 @@ impl SubdiagnosticKind {
                         span_err(value.span().unwrap(), "invalid suggestion style")
                             .help("valid styles are `normal`, `short`, `hidden`, `verbose` and `tool-only`")
                             .emit();
+                        has_errors = true;
                         SuggestionKind::Normal
                     });
 
@@ -762,17 +767,25 @@ impl SubdiagnosticKind {
                             "only `style`, `code` and `applicability` are valid nested attributes",
                         )
                         .emit();
+                    has_errors = true;
                 }
                 (_, SubdiagnosticKind::MultipartSuggestion { .. }) => {
                     span_err(path_span, "invalid nested attribute")
                         .help("only `style` and `applicability` are valid nested attributes")
                         .emit();
+                    has_errors = true;
                 }
                 _ => {
                     span_err(path_span, "invalid nested attribute").emit();
+                    has_errors = true;
                 }
             }
 
+            if has_errors {
+                // Consume the rest of the input to avoid spamming errors
+                let _ = input.parse::<TokenStream>();
+            }
+
             Ok(())
         })?;
 
diff --git a/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs b/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs
index 3151c712566..61724c11745 100644
--- a/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs
+++ b/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs
@@ -50,7 +50,7 @@ enum DiagnosticOnEnum {
 #[derive(Diagnostic)]
 #[diag(no_crate_example, code = "E0123")]
 #[diag = "E0123"]
-//~^ ERROR `#[diag = ...]` is not a valid attribute
+//~^ ERROR expected parentheses: #[diag(...)]
 struct WrongStructAttrStyle {}
 
 #[derive(Diagnostic)]
@@ -62,8 +62,7 @@ struct InvalidStructAttr {}
 
 #[derive(Diagnostic)]
 #[diag("E0123")]
-//~^ ERROR `#[diag("...")]` is not a valid attribute
-//~^^ ERROR diagnostic slug not specified
+//~^ ERROR diagnostic slug not specified
 struct InvalidLitNestedAttr {}
 
 #[derive(Diagnostic)]
@@ -73,27 +72,25 @@ struct InvalidNestedStructAttr {}
 
 #[derive(Diagnostic)]
 #[diag(nonsense("foo"), code = "E0123", slug = "foo")]
-//~^ ERROR `#[diag(nonsense(...))]` is not a valid attribute
-//~^^ ERROR diagnostic slug not specified
+//~^ ERROR diagnostic slug must be the first argument
+//~| ERROR diagnostic slug not specified
 struct InvalidNestedStructAttr1 {}
 
 #[derive(Diagnostic)]
 #[diag(nonsense = "...", code = "E0123", slug = "foo")]
-//~^ ERROR `#[diag(nonsense = ...)]` is not a valid attribute
-//~| ERROR `#[diag(slug = ...)]` is not a valid attribute
+//~^ ERROR unknown argument
 //~| ERROR diagnostic slug not specified
 struct InvalidNestedStructAttr2 {}
 
 #[derive(Diagnostic)]
 #[diag(nonsense = 4, code = "E0123", slug = "foo")]
-//~^ ERROR `#[diag(nonsense = ...)]` is not a valid attribute
-//~| ERROR `#[diag(slug = ...)]` is not a valid attribute
+//~^ ERROR unknown argument
 //~| ERROR diagnostic slug not specified
 struct InvalidNestedStructAttr3 {}
 
 #[derive(Diagnostic)]
 #[diag(no_crate_example, code = "E0123", slug = "foo")]
-//~^ ERROR `#[diag(slug = ...)]` is not a valid attribute
+//~^ ERROR unknown argument
 struct InvalidNestedStructAttr4 {}
 
 #[derive(Diagnostic)]
@@ -118,7 +115,7 @@ struct CodeSpecifiedTwice {}
 
 #[derive(Diagnostic)]
 #[diag(no_crate_example, no_crate::example, code = "E0456")]
-//~^ ERROR `#[diag(no_crate::example)]` is not a valid attribute
+//~^ ERROR diagnostic slug must be the first argument
 struct SlugSpecifiedTwice {}
 
 #[derive(Diagnostic)]
@@ -232,7 +229,7 @@ struct SuggestWithoutCode {
 #[diag(no_crate_example, code = "E0123")]
 struct SuggestWithBadKey {
     #[suggestion(nonsense = "bar")]
-    //~^ ERROR `#[suggestion(nonsense = ...)]` is not a valid attribute
+    //~^ ERROR invalid nested attribute
     //~| ERROR suggestion without `code = "..."`
     suggestion: (Span, Applicability),
 }
@@ -241,7 +238,7 @@ struct SuggestWithBadKey {
 #[diag(no_crate_example, code = "E0123")]
 struct SuggestWithShorthandMsg {
     #[suggestion(msg = "bar")]
-    //~^ ERROR `#[suggestion(msg = ...)]` is not a valid attribute
+    //~^ ERROR invalid nested attribute
     //~| ERROR suggestion without `code = "..."`
     suggestion: (Span, Applicability),
 }
@@ -530,7 +527,7 @@ struct BoolField {
 #[diag(no_crate_example, code = "E0123")]
 struct LabelWithTrailingPath {
     #[label(no_crate_label, foo)]
-    //~^ ERROR `#[label(foo)]` is not a valid attribute
+    //~^ ERROR a diagnostic slug must be the first argument to the attribute
     span: Span,
 }
 
@@ -538,7 +535,7 @@ struct LabelWithTrailingPath {
 #[diag(no_crate_example, code = "E0123")]
 struct LabelWithTrailingNameValue {
     #[label(no_crate_label, foo = "...")]
-    //~^ ERROR `#[label(foo = ...)]` is not a valid attribute
+    //~^ ERROR invalid nested attribute
     span: Span,
 }
 
@@ -546,7 +543,7 @@ struct LabelWithTrailingNameValue {
 #[diag(no_crate_example, code = "E0123")]
 struct LabelWithTrailingList {
     #[label(no_crate_label, foo("..."))]
-    //~^ ERROR `#[label(foo(...))]` is not a valid attribute
+    //~^ ERROR invalid nested attribute
     span: Span,
 }
 
@@ -643,8 +640,8 @@ struct MissingCodeInSuggestion {
 //~^ ERROR `#[multipart_suggestion(...)]` is not a valid attribute
 //~| ERROR cannot find attribute `multipart_suggestion` in this scope
 #[multipart_suggestion()]
-//~^ ERROR `#[multipart_suggestion(...)]` is not a valid attribute
-//~| ERROR cannot find attribute `multipart_suggestion` in this scope
+//~^ ERROR cannot find attribute `multipart_suggestion` in this scope
+//~| ERROR unexpected end of input, unexpected token in nested attribute, expected ident
 struct MultipartSuggestion {
     #[multipart_suggestion(no_crate_suggestion)]
     //~^ ERROR `#[multipart_suggestion(...)]` is not a valid attribute
@@ -698,7 +695,7 @@ struct RawIdentDiagnosticArg {
 #[diag(no_crate_example)]
 struct SubdiagnosticBad {
     #[subdiagnostic(bad)]
-    //~^ ERROR `#[subdiagnostic(...)]` is not a valid attribute
+    //~^ ERROR `eager` is the only supported nested attribute for `subdiagnostic`
     note: Note,
 }
 
@@ -714,7 +711,7 @@ struct SubdiagnosticBadStr {
 #[diag(no_crate_example)]
 struct SubdiagnosticBadTwice {
     #[subdiagnostic(bad, bad)]
-    //~^ ERROR `#[subdiagnostic(...)]` is not a valid attribute
+    //~^ ERROR `eager` is the only supported nested attribute for `subdiagnostic`
     note: Note,
 }
 
@@ -722,7 +719,7 @@ struct SubdiagnosticBadTwice {
 #[diag(no_crate_example)]
 struct SubdiagnosticBadLitStr {
     #[subdiagnostic("bad")]
-    //~^ ERROR `#[subdiagnostic(...)]` is not a valid attribute
+    //~^ ERROR `eager` is the only supported nested attribute for `subdiagnostic`
     note: Note,
 }
 
@@ -797,14 +794,15 @@ struct SuggestionsNoItem {
 struct SuggestionsInvalidItem {
     #[suggestion(code(foo))]
     //~^ ERROR `code(...)` must contain only string literals
+    //~| ERROR unexpected token
     sub: Span,
 }
 
-#[derive(Diagnostic)]
+#[derive(Diagnostic)] //~ ERROR cannot find value `__code_34` in this scope
 #[diag(no_crate_example)]
 struct SuggestionsInvalidLiteral {
     #[suggestion(code = 3)]
-    //~^ ERROR `code = "..."`/`code(...)` must contain only string literals
+    //~^ ERROR expected string literal
     sub: Span,
 }
 
diff --git a/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.stderr b/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.stderr
index 513b675e5dd..041ebdee0ab 100644
--- a/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.stderr
+++ b/tests/ui-fulldeps/session-diagnostic/diagnostic-derive.stderr
@@ -20,11 +20,11 @@ LL |     Bar,
    |
    = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`
 
-error: `#[diag = ...]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:52:1
+error: expected parentheses: #[diag(...)]
+  --> $DIR/diagnostic-derive.rs:52:8
    |
 LL | #[diag = "E0123"]
-   | ^^^^^^^^^^^^^^^^^
+   |        ^
 
 error: `#[nonsense(...)]` is not a valid attribute
   --> $DIR/diagnostic-derive.rs:57:1
@@ -44,35 +44,24 @@ LL | | struct InvalidStructAttr {}
    |
    = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`
 
-error: `#[diag("...")]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:64:8
-   |
-LL | #[diag("E0123")]
-   |        ^^^^^^^
-   |
-   = help: a diagnostic slug is required as the first argument
-
 error: diagnostic slug not specified
   --> $DIR/diagnostic-derive.rs:64:1
    |
 LL | / #[diag("E0123")]
 LL | |
-LL | |
 LL | | struct InvalidLitNestedAttr {}
    | |______________________________^
    |
    = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`
 
-error: `#[diag(nonsense(...))]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:75:8
+error: diagnostic slug must be the first argument
+  --> $DIR/diagnostic-derive.rs:74:16
    |
 LL | #[diag(nonsense("foo"), code = "E0123", slug = "foo")]
-   |        ^^^^^^^^^^^^^^^
-   |
-   = help: a diagnostic slug is required as the first argument
+   |                ^
 
 error: diagnostic slug not specified
-  --> $DIR/diagnostic-derive.rs:75:1
+  --> $DIR/diagnostic-derive.rs:74:1
    |
 LL | / #[diag(nonsense("foo"), code = "E0123", slug = "foo")]
 LL | |
@@ -82,120 +71,102 @@ LL | | struct InvalidNestedStructAttr1 {}
    |
    = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`
 
-error: `#[diag(nonsense = ...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:81:8
+error: unknown argument
+  --> $DIR/diagnostic-derive.rs:80:8
    |
 LL | #[diag(nonsense = "...", code = "E0123", slug = "foo")]
-   |        ^^^^^^^^^^^^^^^^
+   |        ^^^^^^^^
    |
-   = help: only `code` is a valid nested attributes following the slug
-
-error: `#[diag(slug = ...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:81:42
-   |
-LL | #[diag(nonsense = "...", code = "E0123", slug = "foo")]
-   |                                          ^^^^^^^^^^^^
-   |
-   = help: only `code` is a valid nested attributes following the slug
+   = note: only the `code` parameter is valid after the slug
 
 error: diagnostic slug not specified
-  --> $DIR/diagnostic-derive.rs:81:1
+  --> $DIR/diagnostic-derive.rs:80:1
    |
 LL | / #[diag(nonsense = "...", code = "E0123", slug = "foo")]
 LL | |
 LL | |
-LL | |
 LL | | struct InvalidNestedStructAttr2 {}
    | |__________________________________^
    |
    = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`
 
-error: `#[diag(nonsense = ...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:88:8
+error: unknown argument
+  --> $DIR/diagnostic-derive.rs:86:8
    |
 LL | #[diag(nonsense = 4, code = "E0123", slug = "foo")]
-   |        ^^^^^^^^^^^^
-
-error: `#[diag(slug = ...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:88:38
+   |        ^^^^^^^^
    |
-LL | #[diag(nonsense = 4, code = "E0123", slug = "foo")]
-   |                                      ^^^^^^^^^^^^
-   |
-   = help: only `code` is a valid nested attributes following the slug
+   = note: only the `code` parameter is valid after the slug
 
 error: diagnostic slug not specified
-  --> $DIR/diagnostic-derive.rs:88:1
+  --> $DIR/diagnostic-derive.rs:86:1
    |
 LL | / #[diag(nonsense = 4, code = "E0123", slug = "foo")]
 LL | |
 LL | |
-LL | |
 LL | | struct InvalidNestedStructAttr3 {}
    | |__________________________________^
    |
    = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`
 
-error: `#[diag(slug = ...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:95:42
+error: unknown argument
+  --> $DIR/diagnostic-derive.rs:92:42
    |
 LL | #[diag(no_crate_example, code = "E0123", slug = "foo")]
-   |                                          ^^^^^^^^^^^^
+   |                                          ^^^^
    |
-   = help: only `code` is a valid nested attributes following the slug
+   = note: only the `code` parameter is valid after the slug
 
 error: `#[suggestion = ...]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:102:5
+  --> $DIR/diagnostic-derive.rs:99:5
    |
 LL |     #[suggestion = "bar"]
    |     ^^^^^^^^^^^^^^^^^^^^^
 
 error: specified multiple times
-  --> $DIR/diagnostic-derive.rs:109:8
+  --> $DIR/diagnostic-derive.rs:106:8
    |
 LL | #[diag(no_crate_example, code = "E0456")]
    |        ^^^^^^^^^^^^^^^^
    |
 note: previously specified here
-  --> $DIR/diagnostic-derive.rs:108:8
+  --> $DIR/diagnostic-derive.rs:105:8
    |
 LL | #[diag(no_crate_example, code = "E0123")]
    |        ^^^^^^^^^^^^^^^^
 
 error: specified multiple times
-  --> $DIR/diagnostic-derive.rs:109:33
+  --> $DIR/diagnostic-derive.rs:106:26
    |
 LL | #[diag(no_crate_example, code = "E0456")]
-   |                                 ^^^^^^^
+   |                          ^^^^
    |
 note: previously specified here
-  --> $DIR/diagnostic-derive.rs:108:33
+  --> $DIR/diagnostic-derive.rs:105:26
    |
 LL | #[diag(no_crate_example, code = "E0123")]
-   |                                 ^^^^^^^
+   |                          ^^^^
 
 error: specified multiple times
-  --> $DIR/diagnostic-derive.rs:115:49
+  --> $DIR/diagnostic-derive.rs:112:42
    |
 LL | #[diag(no_crate_example, code = "E0456", code = "E0457")]
-   |                                                 ^^^^^^^
+   |                                          ^^^^
    |
 note: previously specified here
-  --> $DIR/diagnostic-derive.rs:115:33
+  --> $DIR/diagnostic-derive.rs:112:26
    |
 LL | #[diag(no_crate_example, code = "E0456", code = "E0457")]
-   |                                 ^^^^^^^
+   |                          ^^^^
 
-error: `#[diag(no_crate::example)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:120:26
+error: diagnostic slug must be the first argument
+  --> $DIR/diagnostic-derive.rs:117:43
    |
 LL | #[diag(no_crate_example, no_crate::example, code = "E0456")]
-   |                          ^^^^^^^^^^^^^^^^^
-   |
-   = help: diagnostic slug must be the first argument
+   |                                           ^
 
 error: diagnostic slug not specified
-  --> $DIR/diagnostic-derive.rs:125:1
+  --> $DIR/diagnostic-derive.rs:122:1
    |
 LL | struct KindNotProvided {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -203,7 +174,7 @@ LL | struct KindNotProvided {}
    = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`
 
 error: diagnostic slug not specified
-  --> $DIR/diagnostic-derive.rs:128:1
+  --> $DIR/diagnostic-derive.rs:125:1
    |
 LL | / #[diag(code = "E0456")]
 LL | |
@@ -213,31 +184,31 @@ LL | | struct SlugNotProvided {}
    = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`
 
 error: the `#[primary_span]` attribute can only be applied to fields of type `Span` or `MultiSpan`
-  --> $DIR/diagnostic-derive.rs:139:5
+  --> $DIR/diagnostic-derive.rs:136:5
    |
 LL |     #[primary_span]
    |     ^^^^^^^^^^^^^^^
 
 error: `#[nonsense]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:147:5
+  --> $DIR/diagnostic-derive.rs:144:5
    |
 LL |     #[nonsense]
    |     ^^^^^^^^^^^
 
 error: the `#[label(...)]` attribute can only be applied to fields of type `Span` or `MultiSpan`
-  --> $DIR/diagnostic-derive.rs:164:5
+  --> $DIR/diagnostic-derive.rs:161:5
    |
 LL |     #[label(no_crate_label)]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `name` doesn't refer to a field on this type
-  --> $DIR/diagnostic-derive.rs:172:46
+  --> $DIR/diagnostic-derive.rs:169:46
    |
 LL |     #[suggestion(no_crate_suggestion, code = "{name}")]
    |                                              ^^^^^^^^
 
 error: invalid format string: expected `'}'` but string was terminated
-  --> $DIR/diagnostic-derive.rs:177:10
+  --> $DIR/diagnostic-derive.rs:174:10
    |
 LL | #[derive(Diagnostic)]
    |          ^^^^^^^^^^ expected `'}'` in format string
@@ -246,7 +217,7 @@ LL | #[derive(Diagnostic)]
    = note: this error originates in the derive macro `Diagnostic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: invalid format string: unmatched `}` found
-  --> $DIR/diagnostic-derive.rs:187:10
+  --> $DIR/diagnostic-derive.rs:184:10
    |
 LL | #[derive(Diagnostic)]
    |          ^^^^^^^^^^ unmatched `}` in format string
@@ -255,47 +226,47 @@ LL | #[derive(Diagnostic)]
    = note: this error originates in the derive macro `Diagnostic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: the `#[label(...)]` attribute can only be applied to fields of type `Span` or `MultiSpan`
-  --> $DIR/diagnostic-derive.rs:207:5
+  --> $DIR/diagnostic-derive.rs:204:5
    |
 LL |     #[label(no_crate_label)]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: suggestion without `code = "..."`
-  --> $DIR/diagnostic-derive.rs:226:5
+  --> $DIR/diagnostic-derive.rs:223:5
    |
 LL |     #[suggestion(no_crate_suggestion)]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: `#[suggestion(nonsense = ...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:234:18
+error: invalid nested attribute
+  --> $DIR/diagnostic-derive.rs:231:18
    |
 LL |     #[suggestion(nonsense = "bar")]
-   |                  ^^^^^^^^^^^^^^^^
+   |                  ^^^^^^^^
    |
    = help: only `style`, `code` and `applicability` are valid nested attributes
 
 error: suggestion without `code = "..."`
-  --> $DIR/diagnostic-derive.rs:234:5
+  --> $DIR/diagnostic-derive.rs:231:5
    |
 LL |     #[suggestion(nonsense = "bar")]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: `#[suggestion(msg = ...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:243:18
+error: invalid nested attribute
+  --> $DIR/diagnostic-derive.rs:240:18
    |
 LL |     #[suggestion(msg = "bar")]
-   |                  ^^^^^^^^^^^
+   |                  ^^^
    |
    = help: only `style`, `code` and `applicability` are valid nested attributes
 
 error: suggestion without `code = "..."`
-  --> $DIR/diagnostic-derive.rs:243:5
+  --> $DIR/diagnostic-derive.rs:240:5
    |
 LL |     #[suggestion(msg = "bar")]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: wrong field type for suggestion
-  --> $DIR/diagnostic-derive.rs:266:5
+  --> $DIR/diagnostic-derive.rs:263:5
    |
 LL | /     #[suggestion(no_crate_suggestion, code = "This is suggested code")]
 LL | |
@@ -305,81 +276,79 @@ LL | |     suggestion: Applicability,
    = help: `#[suggestion(...)]` should be applied to fields of type `Span` or `(Span, Applicability)`
 
 error: specified multiple times
-  --> $DIR/diagnostic-derive.rs:282:24
+  --> $DIR/diagnostic-derive.rs:279:24
    |
 LL |     suggestion: (Span, Span, Applicability),
    |                        ^^^^
    |
 note: previously specified here
-  --> $DIR/diagnostic-derive.rs:282:18
+  --> $DIR/diagnostic-derive.rs:279:18
    |
 LL |     suggestion: (Span, Span, Applicability),
    |                  ^^^^
 
 error: specified multiple times
-  --> $DIR/diagnostic-derive.rs:290:33
+  --> $DIR/diagnostic-derive.rs:287:33
    |
 LL |     suggestion: (Applicability, Applicability, Span),
    |                                 ^^^^^^^^^^^^^
    |
 note: previously specified here
-  --> $DIR/diagnostic-derive.rs:290:18
+  --> $DIR/diagnostic-derive.rs:287:18
    |
 LL |     suggestion: (Applicability, Applicability, Span),
    |                  ^^^^^^^^^^^^^
 
 error: `#[label = ...]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:297:5
+  --> $DIR/diagnostic-derive.rs:294:5
    |
 LL |     #[label = "bar"]
    |     ^^^^^^^^^^^^^^^^
 
 error: specified multiple times
-  --> $DIR/diagnostic-derive.rs:448:53
+  --> $DIR/diagnostic-derive.rs:445:5
    |
 LL |     #[suggestion(no_crate_suggestion, code = "...", applicability = "maybe-incorrect")]
-   |                                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 note: previously specified here
-  --> $DIR/diagnostic-derive.rs:450:24
+  --> $DIR/diagnostic-derive.rs:447:24
    |
 LL |     suggestion: (Span, Applicability),
    |                        ^^^^^^^^^^^^^
 
 error: invalid applicability
-  --> $DIR/diagnostic-derive.rs:456:53
+  --> $DIR/diagnostic-derive.rs:453:69
    |
 LL |     #[suggestion(no_crate_suggestion, code = "...", applicability = "batman")]
-   |                                                     ^^^^^^^^^^^^^^^^^^^^^^^^
+   |                                                                     ^^^^^^^^
 
 error: the `#[help(...)]` attribute can only be applied to fields of type `Span`, `bool` or `()`
-  --> $DIR/diagnostic-derive.rs:523:5
+  --> $DIR/diagnostic-derive.rs:520:5
    |
 LL |     #[help(no_crate_help)]
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
-error: `#[label(foo)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:532:29
+error: a diagnostic slug must be the first argument to the attribute
+  --> $DIR/diagnostic-derive.rs:529:32
    |
 LL |     #[label(no_crate_label, foo)]
-   |                             ^^^
-   |
-   = help: a diagnostic slug must be the first argument to the attribute
+   |                                ^
 
-error: `#[label(foo = ...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:540:29
+error: invalid nested attribute
+  --> $DIR/diagnostic-derive.rs:537:29
    |
 LL |     #[label(no_crate_label, foo = "...")]
-   |                             ^^^^^^^^^^^
+   |                             ^^^
 
-error: `#[label(foo(...))]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:548:29
+error: invalid nested attribute
+  --> $DIR/diagnostic-derive.rs:545:29
    |
 LL |     #[label(no_crate_label, foo("..."))]
-   |                             ^^^^^^^^^^
+   |                             ^^^
 
 error: `#[primary_span]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:560:5
+  --> $DIR/diagnostic-derive.rs:557:5
    |
 LL |     #[primary_span]
    |     ^^^^^^^^^^^^^^^
@@ -387,13 +356,13 @@ LL |     #[primary_span]
    = help: the `primary_span` field attribute is not valid for lint diagnostics
 
 error: `#[error(...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:580:1
+  --> $DIR/diagnostic-derive.rs:577:1
    |
 LL | #[error(no_crate_example, code = "E0123")]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: diagnostic slug not specified
-  --> $DIR/diagnostic-derive.rs:580:1
+  --> $DIR/diagnostic-derive.rs:577:1
    |
 LL | / #[error(no_crate_example, code = "E0123")]
 LL | |
@@ -405,13 +374,13 @@ LL | | struct ErrorAttribute {}
    = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`
 
 error: `#[warn_(...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:587:1
+  --> $DIR/diagnostic-derive.rs:584:1
    |
 LL | #[warn_(no_crate_example, code = "E0123")]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: diagnostic slug not specified
-  --> $DIR/diagnostic-derive.rs:587:1
+  --> $DIR/diagnostic-derive.rs:584:1
    |
 LL | / #[warn_(no_crate_example, code = "E0123")]
 LL | |
@@ -423,13 +392,13 @@ LL | | struct WarnAttribute {}
    = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`
 
 error: `#[lint(...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:594:1
+  --> $DIR/diagnostic-derive.rs:591:1
    |
 LL | #[lint(no_crate_example, code = "E0123")]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: diagnostic slug not specified
-  --> $DIR/diagnostic-derive.rs:594:1
+  --> $DIR/diagnostic-derive.rs:591:1
    |
 LL | / #[lint(no_crate_example, code = "E0123")]
 LL | |
@@ -441,19 +410,19 @@ LL | | struct LintAttributeOnSessionDiag {}
    = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(hir_analysis_example_error)]`
 
 error: `#[lint(...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:601:1
+  --> $DIR/diagnostic-derive.rs:598:1
    |
 LL | #[lint(no_crate_example, code = "E0123")]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `#[lint(...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:601:1
+  --> $DIR/diagnostic-derive.rs:598:1
    |
 LL | #[lint(no_crate_example, code = "E0123")]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: diagnostic slug not specified
-  --> $DIR/diagnostic-derive.rs:601:1
+  --> $DIR/diagnostic-derive.rs:598:1
    |
 LL | / #[lint(no_crate_example, code = "E0123")]
 LL | |
@@ -466,19 +435,19 @@ LL | | struct LintAttributeOnLintDiag {}
    = help: specify the slug as the first argument to the attribute, such as `#[diag(compiletest_example)]`
 
 error: specified multiple times
-  --> $DIR/diagnostic-derive.rs:611:53
+  --> $DIR/diagnostic-derive.rs:608:5
    |
 LL |     #[suggestion(no_crate_suggestion, code = "...", code = ",,,")]
-   |                                                     ^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 note: previously specified here
-  --> $DIR/diagnostic-derive.rs:611:39
+  --> $DIR/diagnostic-derive.rs:608:5
    |
 LL |     #[suggestion(no_crate_suggestion, code = "...", code = ",,,")]
-   |                                       ^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: wrong types for suggestion
-  --> $DIR/diagnostic-derive.rs:620:24
+  --> $DIR/diagnostic-derive.rs:617:24
    |
 LL |     suggestion: (Span, usize),
    |                        ^^^^^
@@ -486,7 +455,7 @@ LL |     suggestion: (Span, usize),
    = help: `#[suggestion(...)]` on a tuple field must be applied to fields of type `(Span, Applicability)`
 
 error: wrong types for suggestion
-  --> $DIR/diagnostic-derive.rs:628:17
+  --> $DIR/diagnostic-derive.rs:625:17
    |
 LL |     suggestion: (Span,),
    |                 ^^^^^^^
@@ -494,13 +463,13 @@ LL |     suggestion: (Span,),
    = help: `#[suggestion(...)]` on a tuple field must be applied to fields of type `(Span, Applicability)`
 
 error: suggestion without `code = "..."`
-  --> $DIR/diagnostic-derive.rs:635:5
+  --> $DIR/diagnostic-derive.rs:632:5
    |
 LL |     #[suggestion(no_crate_suggestion)]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `#[multipart_suggestion(...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:642:1
+  --> $DIR/diagnostic-derive.rs:639:1
    |
 LL | #[multipart_suggestion(no_crate_suggestion)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -508,23 +477,21 @@ LL | #[multipart_suggestion(no_crate_suggestion)]
    = help: consider creating a `Subdiagnostic` instead
 
 error: `#[multipart_suggestion(...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:645:1
-   |
-LL | #[multipart_suggestion()]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = help: consider creating a `Subdiagnostic` instead
-
-error: `#[multipart_suggestion(...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:649:5
+  --> $DIR/diagnostic-derive.rs:646:5
    |
 LL |     #[multipart_suggestion(no_crate_suggestion)]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider creating a `Subdiagnostic` instead
 
+error: unexpected end of input, unexpected token in nested attribute, expected ident
+  --> $DIR/diagnostic-derive.rs:642:24
+   |
+LL | #[multipart_suggestion()]
+   |                        ^
+
 error: `#[suggestion(...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:657:1
+  --> $DIR/diagnostic-derive.rs:654:1
    |
 LL | #[suggestion(no_crate_suggestion, code = "...")]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -532,45 +499,39 @@ LL | #[suggestion(no_crate_suggestion, code = "...")]
    = help: `#[label]` and `#[suggestion]` can only be applied to fields
 
 error: `#[label]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:666:1
+  --> $DIR/diagnostic-derive.rs:663:1
    |
 LL | #[label]
    | ^^^^^^^^
    |
    = help: `#[label]` and `#[suggestion]` can only be applied to fields
 
-error: `#[subdiagnostic(...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:700:5
+error: `eager` is the only supported nested attribute for `subdiagnostic`
+  --> $DIR/diagnostic-derive.rs:697:7
    |
 LL |     #[subdiagnostic(bad)]
-   |     ^^^^^^^^^^^^^^^^^^^^^
-   |
-   = help: `eager` is the only supported nested attribute for `subdiagnostic`
+   |       ^^^^^^^^^^^^^^^^^^
 
 error: `#[subdiagnostic = ...]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:708:5
+  --> $DIR/diagnostic-derive.rs:705:5
    |
 LL |     #[subdiagnostic = "bad"]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: `#[subdiagnostic(...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:716:5
+error: `eager` is the only supported nested attribute for `subdiagnostic`
+  --> $DIR/diagnostic-derive.rs:713:7
    |
 LL |     #[subdiagnostic(bad, bad)]
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = help: `eager` is the only supported nested attribute for `subdiagnostic`
+   |       ^^^^^^^^^^^^^^^^^^^^^^^
 
-error: `#[subdiagnostic(...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:724:5
+error: `eager` is the only supported nested attribute for `subdiagnostic`
+  --> $DIR/diagnostic-derive.rs:721:7
    |
 LL |     #[subdiagnostic("bad")]
-   |     ^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = help: `eager` is the only supported nested attribute for `subdiagnostic`
+   |       ^^^^^^^^^^^^^^^^^^^^
 
 error: `#[subdiagnostic(...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:732:5
+  --> $DIR/diagnostic-derive.rs:729:5
    |
 LL |     #[subdiagnostic(eager)]
    |     ^^^^^^^^^^^^^^^^^^^^^^^
@@ -578,25 +539,31 @@ LL |     #[subdiagnostic(eager)]
    = help: eager subdiagnostics are not supported on lints
 
 error: expected at least one string literal for `code(...)`
-  --> $DIR/diagnostic-derive.rs:790:18
+  --> $DIR/diagnostic-derive.rs:787:23
    |
 LL |     #[suggestion(code())]
-   |                  ^^^^^^
+   |                       ^
 
 error: `code(...)` must contain only string literals
-  --> $DIR/diagnostic-derive.rs:798:23
+  --> $DIR/diagnostic-derive.rs:795:23
    |
 LL |     #[suggestion(code(foo))]
    |                       ^^^
 
-error: `code = "..."`/`code(...)` must contain only string literals
-  --> $DIR/diagnostic-derive.rs:806:18
+error: unexpected token
+  --> $DIR/diagnostic-derive.rs:795:23
+   |
+LL |     #[suggestion(code(foo))]
+   |                       ^^^
+
+error: expected string literal
+  --> $DIR/diagnostic-derive.rs:804:25
    |
 LL |     #[suggestion(code = 3)]
-   |                  ^^^^^^^^
+   |                         ^
 
 error: `#[suggestion(...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:821:5
+  --> $DIR/diagnostic-derive.rs:819:5
    |
 LL |     #[suggestion(no_crate_suggestion, code = "")]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -612,61 +579,69 @@ LL | #[nonsense(no_crate_example, code = "E0123")]
    |   ^^^^^^^^
 
 error: cannot find attribute `nonsense` in this scope
-  --> $DIR/diagnostic-derive.rs:147:7
+  --> $DIR/diagnostic-derive.rs:144:7
    |
 LL |     #[nonsense]
    |       ^^^^^^^^
 
 error: cannot find attribute `error` in this scope
-  --> $DIR/diagnostic-derive.rs:580:3
+  --> $DIR/diagnostic-derive.rs:577:3
    |
 LL | #[error(no_crate_example, code = "E0123")]
    |   ^^^^^
 
 error: cannot find attribute `warn_` in this scope
-  --> $DIR/diagnostic-derive.rs:587:3
+  --> $DIR/diagnostic-derive.rs:584:3
    |
 LL | #[warn_(no_crate_example, code = "E0123")]
    |   ^^^^^ help: a built-in attribute with a similar name exists: `warn`
 
 error: cannot find attribute `lint` in this scope
-  --> $DIR/diagnostic-derive.rs:594:3
+  --> $DIR/diagnostic-derive.rs:591:3
    |
 LL | #[lint(no_crate_example, code = "E0123")]
    |   ^^^^ help: a built-in attribute with a similar name exists: `link`
 
 error: cannot find attribute `lint` in this scope
-  --> $DIR/diagnostic-derive.rs:601:3
+  --> $DIR/diagnostic-derive.rs:598:3
    |
 LL | #[lint(no_crate_example, code = "E0123")]
    |   ^^^^ help: a built-in attribute with a similar name exists: `link`
 
 error: cannot find attribute `multipart_suggestion` in this scope
-  --> $DIR/diagnostic-derive.rs:642:3
+  --> $DIR/diagnostic-derive.rs:639:3
    |
 LL | #[multipart_suggestion(no_crate_suggestion)]
    |   ^^^^^^^^^^^^^^^^^^^^
 
 error: cannot find attribute `multipart_suggestion` in this scope
-  --> $DIR/diagnostic-derive.rs:645:3
+  --> $DIR/diagnostic-derive.rs:642:3
    |
 LL | #[multipart_suggestion()]
    |   ^^^^^^^^^^^^^^^^^^^^
 
 error: cannot find attribute `multipart_suggestion` in this scope
-  --> $DIR/diagnostic-derive.rs:649:7
+  --> $DIR/diagnostic-derive.rs:646:7
    |
 LL |     #[multipart_suggestion(no_crate_suggestion)]
    |       ^^^^^^^^^^^^^^^^^^^^
 
 error[E0425]: cannot find value `nonsense` in module `crate::fluent_generated`
-  --> $DIR/diagnostic-derive.rs:70:8
+  --> $DIR/diagnostic-derive.rs:69:8
    |
 LL | #[diag(nonsense, code = "E0123")]
    |        ^^^^^^^^ not found in `crate::fluent_generated`
 
+error[E0425]: cannot find value `__code_34` in this scope
+  --> $DIR/diagnostic-derive.rs:801:10
+   |
+LL | #[derive(Diagnostic)]
+   |          ^^^^^^^^^^ not found in this scope
+   |
+   = note: this error originates in the derive macro `Diagnostic` (in Nightly builds, run with -Z macro-backtrace for more info)
+
 error[E0277]: the trait bound `Hello: IntoDiagnosticArg` is not satisfied
-  --> $DIR/diagnostic-derive.rs:341:10
+  --> $DIR/diagnostic-derive.rs:338:10
    |
 LL | #[derive(Diagnostic)]
    |          ^^^^^^^^^^ the trait `IntoDiagnosticArg` is not implemented for `Hello`
@@ -676,7 +651,7 @@ note: required by a bound in `DiagnosticBuilder::<'a, G>::set_arg`
   --> $COMPILER_DIR/rustc_errors/src/diagnostic_builder.rs:LL:CC
    = note: this error originates in the derive macro `Diagnostic` which comes from the expansion of the macro `forward` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 85 previous errors
+error: aborting due to 84 previous errors
 
 Some errors have detailed explanations: E0277, E0425.
 For more information about an error, try `rustc --explain E0277`.
diff --git a/tests/ui-fulldeps/session-diagnostic/subdiagnostic-derive.stderr b/tests/ui-fulldeps/session-diagnostic/subdiagnostic-derive.stderr
index 343134af6bc..d8bf0ba413c 100644
--- a/tests/ui-fulldeps/session-diagnostic/subdiagnostic-derive.stderr
+++ b/tests/ui-fulldeps/session-diagnostic/subdiagnostic-derive.stderr
@@ -26,11 +26,11 @@ error: `#[label = ...]` is not a valid attribute
 LL | #[label = "..."]
    | ^^^^^^^^^^^^^^^^
 
-error: `#[label(bug = ...)]` is not a valid attribute
+error: invalid nested attribute
   --> $DIR/subdiagnostic-derive.rs:84:9
    |
 LL | #[label(bug = "...")]
-   |         ^^^^^^^^^^^
+   |         ^^^
 
 error: diagnostic slug must be first argument of a `#[label(...)]` attribute
   --> $DIR/subdiagnostic-derive.rs:84:1
@@ -38,23 +38,17 @@ error: diagnostic slug must be first argument of a `#[label(...)]` attribute
 LL | #[label(bug = "...")]
    | ^^^^^^^^^^^^^^^^^^^^^
 
-error: `#[label("...")]` is not a valid attribute
+error: unexpected literal in nested attribute, expected ident
   --> $DIR/subdiagnostic-derive.rs:94:9
    |
 LL | #[label("...")]
    |         ^^^^^
 
-error: diagnostic slug must be first argument of a `#[label(...)]` attribute
-  --> $DIR/subdiagnostic-derive.rs:94:1
-   |
-LL | #[label("...")]
-   | ^^^^^^^^^^^^^^^
-
-error: `#[label(slug = ...)]` is not a valid attribute
+error: invalid nested attribute
   --> $DIR/subdiagnostic-derive.rs:104:9
    |
 LL | #[label(slug = 4)]
-   |         ^^^^^^^^
+   |         ^^^^
 
 error: diagnostic slug must be first argument of a `#[label(...)]` attribute
   --> $DIR/subdiagnostic-derive.rs:104:1
@@ -62,11 +56,11 @@ error: diagnostic slug must be first argument of a `#[label(...)]` attribute
 LL | #[label(slug = 4)]
    | ^^^^^^^^^^^^^^^^^^
 
-error: `#[label(slug(...))]` is not a valid attribute
+error: invalid nested attribute
   --> $DIR/subdiagnostic-derive.rs:114:9
    |
 LL | #[label(slug("..."))]
-   |         ^^^^^^^^^^^
+   |         ^^^^
 
 error: diagnostic slug must be first argument of a `#[label(...)]` attribute
   --> $DIR/subdiagnostic-derive.rs:114:1
@@ -74,23 +68,23 @@ error: diagnostic slug must be first argument of a `#[label(...)]` attribute
 LL | #[label(slug("..."))]
    | ^^^^^^^^^^^^^^^^^^^^^
 
-error: diagnostic slug must be first argument of a `#[label(...)]` attribute
-  --> $DIR/subdiagnostic-derive.rs:134:1
+error: unexpected end of input, unexpected token in nested attribute, expected ident
+  --> $DIR/subdiagnostic-derive.rs:134:9
    |
 LL | #[label()]
-   | ^^^^^^^^^^
+   |         ^
 
-error: `#[label(code = ...)]` is not a valid attribute
+error: invalid nested attribute
   --> $DIR/subdiagnostic-derive.rs:143:27
    |
 LL | #[label(no_crate_example, code = "...")]
-   |                           ^^^^^^^^^^^^
+   |                           ^^^^
 
-error: `#[label(applicability = ...)]` is not a valid attribute
+error: invalid nested attribute
   --> $DIR/subdiagnostic-derive.rs:152:27
    |
 LL | #[label(no_crate_example, applicability = "machine-applicable")]
-   |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |                           ^^^^^^^^^^^^^
 
 error: unsupported type attribute for subdiagnostic enum
   --> $DIR/subdiagnostic-derive.rs:161:1
@@ -122,11 +116,11 @@ error: `#[bar(...)]` is not a valid attribute
 LL |     #[bar("...")]
    |     ^^^^^^^^^^^^^
 
-error: `#[label(code = ...)]` is not a valid attribute
+error: invalid nested attribute
   --> $DIR/subdiagnostic-derive.rs:223:13
    |
 LL |     #[label(code = "...")]
-   |             ^^^^^^^^^^^^
+   |             ^^^^
 
 error: diagnostic slug must be first argument of a `#[label(...)]` attribute
   --> $DIR/subdiagnostic-derive.rs:223:5
@@ -190,13 +184,11 @@ LL | |     b: u64,
 LL | | }
    | |_^
 
-error: `#[label(no_crate::example)]` is not a valid attribute
-  --> $DIR/subdiagnostic-derive.rs:325:27
+error: a diagnostic slug must be the first argument to the attribute
+  --> $DIR/subdiagnostic-derive.rs:325:44
    |
 LL | #[label(no_crate_example, no_crate::example)]
-   |                           ^^^^^^^^^^^^^^^^^
-   |
-   = help: a diagnostic slug must be the first argument to the attribute
+   |                                            ^
 
 error: specified multiple times
   --> $DIR/subdiagnostic-derive.rs:338:5
@@ -217,16 +209,16 @@ LL | struct AG {
    |        ^^
 
 error: specified multiple times
-  --> $DIR/subdiagnostic-derive.rs:381:46
+  --> $DIR/subdiagnostic-derive.rs:381:1
    |
 LL | #[suggestion(no_crate_example, code = "...", code = "...")]
-   |                                              ^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 note: previously specified here
-  --> $DIR/subdiagnostic-derive.rs:381:32
+  --> $DIR/subdiagnostic-derive.rs:381:1
    |
 LL | #[suggestion(no_crate_example, code = "...", code = "...")]
-   |                                ^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: specified multiple times
   --> $DIR/subdiagnostic-derive.rs:399:5
@@ -253,10 +245,10 @@ LL | #[suggestion(no_crate_example)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: invalid applicability
-  --> $DIR/subdiagnostic-derive.rs:432:46
+  --> $DIR/subdiagnostic-derive.rs:432:62
    |
 LL | #[suggestion(no_crate_example, code = "...", applicability = "foo")]
-   |                                              ^^^^^^^^^^^^^^^^^^^^^
+   |                                                              ^^^^^
 
 error: suggestion without `#[primary_span]` field
   --> $DIR/subdiagnostic-derive.rs:450:1
@@ -314,11 +306,11 @@ LL | |     var: String,
 LL | | }
    | |_^
 
-error: `#[multipart_suggestion(code = ...)]` is not a valid attribute
+error: invalid nested attribute
   --> $DIR/subdiagnostic-derive.rs:538:42
    |
 LL | #[multipart_suggestion(no_crate_example, code = "...", applicability = "machine-applicable")]
-   |                                          ^^^^^^^^^^^^
+   |                                          ^^^^
    |
    = help: only `style` and `applicability` are valid nested attributes
 
@@ -339,11 +331,11 @@ error: `#[suggestion_part(...)]` attribute without `code = "..."`
 LL |     #[suggestion_part]
    |     ^^^^^^^^^^^^^^^^^^
 
-error: `#[suggestion_part(...)]` attribute without `code = "..."`
-  --> $DIR/subdiagnostic-derive.rs:556:5
+error: unexpected end of input, unexpected token in nested attribute, expected ident
+  --> $DIR/subdiagnostic-derive.rs:556:23
    |
 LL |     #[suggestion_part()]
-   |     ^^^^^^^^^^^^^^^^^^^^
+   |                       ^
 
 error: `#[primary_span]` is not a valid attribute
   --> $DIR/subdiagnostic-derive.rs:565:5
@@ -371,19 +363,11 @@ error: `#[suggestion_part(...)]` attribute without `code = "..."`
 LL |     #[suggestion_part]
    |     ^^^^^^^^^^^^^^^^^^
 
-error: `#[suggestion_part(...)]` attribute without `code = "..."`
-  --> $DIR/subdiagnostic-derive.rs:576:5
-   |
-LL |     #[suggestion_part()]
-   |     ^^^^^^^^^^^^^^^^^^^^
-
-error: `#[suggestion_part(foo = ...)]` is not a valid attribute
+error: `code` is the only valid nested attribute
   --> $DIR/subdiagnostic-derive.rs:579:23
    |
 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:582:5
@@ -397,17 +381,29 @@ error: the `#[suggestion_part(...)]` attribute can only be applied to fields of
 LL |     #[suggestion_part()]
    |     ^^^^^^^^^^^^^^^^^^^^
 
+error: unexpected end of input, unexpected token in nested attribute, expected ident
+  --> $DIR/subdiagnostic-derive.rs:576:23
+   |
+LL |     #[suggestion_part()]
+   |                       ^
+
+error: expected `,`
+  --> $DIR/subdiagnostic-derive.rs:579:27
+   |
+LL |     #[suggestion_part(foo = "bar")]
+   |                           ^
+
 error: specified multiple times
-  --> $DIR/subdiagnostic-derive.rs:593:37
+  --> $DIR/subdiagnostic-derive.rs:593:5
    |
 LL |     #[suggestion_part(code = "...", code = ",,,")]
-   |                                     ^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 note: previously specified here
-  --> $DIR/subdiagnostic-derive.rs:593:23
+  --> $DIR/subdiagnostic-derive.rs:593:5
    |
 LL |     #[suggestion_part(code = "...", code = ",,,")]
-   |                       ^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `#[applicability]` has no effect if all `#[suggestion]`/`#[multipart_suggestion]` attributes have a static `applicability = "..."`
   --> $DIR/subdiagnostic-derive.rs:622:5
@@ -416,46 +412,64 @@ LL |     #[applicability]
    |     ^^^^^^^^^^^^^^^^
 
 error: expected exactly one string literal for `code = ...`
-  --> $DIR/subdiagnostic-derive.rs:670:23
+  --> $DIR/subdiagnostic-derive.rs:670:34
    |
 LL |     #[suggestion_part(code("foo"))]
-   |                       ^^^^^^^^^^^
+   |                                  ^
+
+error: unexpected token
+  --> $DIR/subdiagnostic-derive.rs:670:28
+   |
+LL |     #[suggestion_part(code("foo"))]
+   |                            ^^^^^
 
 error: expected exactly one string literal for `code = ...`
-  --> $DIR/subdiagnostic-derive.rs:679:23
+  --> $DIR/subdiagnostic-derive.rs:679:41
    |
 LL |     #[suggestion_part(code("foo", "bar"))]
-   |                       ^^^^^^^^^^^^^^^^^^
+   |                                         ^
+
+error: unexpected token
+  --> $DIR/subdiagnostic-derive.rs:679:28
+   |
+LL |     #[suggestion_part(code("foo", "bar"))]
+   |                            ^^^^^
 
 error: expected exactly one string literal for `code = ...`
-  --> $DIR/subdiagnostic-derive.rs:688:23
+  --> $DIR/subdiagnostic-derive.rs:688:30
    |
 LL |     #[suggestion_part(code(3))]
-   |                       ^^^^^^^
+   |                              ^
+
+error: unexpected token
+  --> $DIR/subdiagnostic-derive.rs:688:28
+   |
+LL |     #[suggestion_part(code(3))]
+   |                            ^
 
 error: expected exactly one string literal for `code = ...`
-  --> $DIR/subdiagnostic-derive.rs:697:23
+  --> $DIR/subdiagnostic-derive.rs:697:29
    |
 LL |     #[suggestion_part(code())]
-   |                       ^^^^^^
+   |                             ^
 
-error: `code = "..."`/`code(...)` must contain only string literals
-  --> $DIR/subdiagnostic-derive.rs:706:23
+error: expected string literal
+  --> $DIR/subdiagnostic-derive.rs:706:30
    |
 LL |     #[suggestion_part(code = 3)]
-   |                       ^^^^^^^^
+   |                              ^
 
 error: specified multiple times
-  --> $DIR/subdiagnostic-derive.rs:748:61
+  --> $DIR/subdiagnostic-derive.rs:748:1
    |
 LL | #[suggestion(no_crate_example, code = "", style = "hidden", style = "normal")]
-   |                                                             ^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 note: previously specified here
-  --> $DIR/subdiagnostic-derive.rs:748:43
+  --> $DIR/subdiagnostic-derive.rs:748:1
    |
 LL | #[suggestion(no_crate_example, code = "", style = "hidden", style = "normal")]
-   |                                           ^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `#[suggestion_hidden(...)]` is not a valid attribute
   --> $DIR/subdiagnostic-derive.rs:757:1
@@ -481,25 +495,29 @@ LL | #[suggestion(no_crate_example, code = "", style = "foo")]
    |
    = help: valid styles are `normal`, `short`, `hidden`, `verbose` and `tool-only`
 
-error: `#[suggestion(style = ...)]` is not a valid attribute
-  --> $DIR/subdiagnostic-derive.rs:781:43
+error: expected `= "xxx"`
+  --> $DIR/subdiagnostic-derive.rs:781:49
    |
 LL | #[suggestion(no_crate_example, code = "", style = 42)]
-   |                                           ^^^^^^^^^^
+   |                                                 ^
 
-error: `#[suggestion(style)]` is not a valid attribute
-  --> $DIR/subdiagnostic-derive.rs:789:43
+error: a diagnostic slug must be the first argument to the attribute
+  --> $DIR/subdiagnostic-derive.rs:789:48
    |
 LL | #[suggestion(no_crate_example, code = "", style)]
-   |                                           ^^^^^
-   |
-   = help: a diagnostic slug must be the first argument to the attribute
+   |                                                ^
 
-error: `#[suggestion(style(...))]` is not a valid attribute
-  --> $DIR/subdiagnostic-derive.rs:797:43
+error: expected `= "xxx"`
+  --> $DIR/subdiagnostic-derive.rs:797:48
    |
 LL | #[suggestion(no_crate_example, code = "", style("foo"))]
-   |                                           ^^^^^^^^^^^^
+   |                                                ^
+
+error: expected `,`
+  --> $DIR/subdiagnostic-derive.rs:797:48
+   |
+LL | #[suggestion(no_crate_example, code = "", style("foo"))]
+   |                                                ^
 
 error: `#[primary_span]` is not a valid attribute
   --> $DIR/subdiagnostic-derive.rs:808:5
@@ -582,6 +600,14 @@ error[E0425]: cannot find value `slug` in module `crate::fluent_generated`
 LL | #[label(slug)]
    |         ^^^^ not found in `crate::fluent_generated`
 
-error: aborting due to 81 previous errors
+error[E0425]: cannot find value `__code_29` in this scope
+  --> $DIR/subdiagnostic-derive.rs:703:10
+   |
+LL | #[derive(Subdiagnostic)]
+   |          ^^^^^^^^^^^^^ not found in this scope
+   |
+   = note: this error originates in the derive macro `Subdiagnostic` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 86 previous errors
 
 For more information about this error, try `rustc --explain E0425`.