Merge InvalidTarget and InvalidTargetLint diagnostics

Author: JonathanBrouwer

compiler/rustc_attr_parsing/src/errors.rs

@@ -132,26 +132,6 @@ pub(crate) struct EmptyAttributeList {
     pub valid_without_list: bool,
 }
 
-#[derive(Diagnostic)]
-#[diag("`#[{$name}]` attribute cannot be used on {$target}")]
-#[warning(
-    "this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!"
-)]
-#[help("`#[{$name}]` can {$only}be applied to {$applied}")]
-pub(crate) struct InvalidTargetLint {
-    pub name: String,
-    pub target: &'static str,
-    pub applied: DiagArgValue,
-    pub only: &'static str,
-    #[suggestion(
-        "remove the attribute",
-        code = "",
-        applicability = "machine-applicable",
-        style = "tool-only"
-    )]
-    pub attr_span: Span,
-}
-
 #[derive(Diagnostic)]
 #[diag(
     "{$is_used_as_inner ->

compiler/rustc_attr_parsing/src/session_diagnostics.rs

@@ -353,6 +353,10 @@ pub(crate) struct InvalidTarget {
     pub target: &'static str,
     pub applied: DiagArgValue,
     pub only: &'static str,
+    #[warning(
+        "this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!"
+    )]
+    pub previously_accepted: bool,
 }
 
 #[derive(Diagnostic)]

compiler/rustc_attr_parsing/src/target_checking.rs

@@ -9,8 +9,7 @@ use rustc_span::{BytePos, FileName, RemapPathScopeComponents, Span, Symbol, sym}
 
 use crate::context::AcceptContext;
 use crate::errors::{
-    InvalidAttrAtCrateLevel, InvalidTargetLint, ItemFollowingInnerAttr,
-    UnsupportedAttributesInWhere,
+    InvalidAttrAtCrateLevel, ItemFollowingInnerAttr, UnsupportedAttributesInWhere,
 };
 use crate::session_diagnostics::InvalidTarget;
 use crate::target_checking::Policy::Allow;
@@ -150,14 +149,15 @@ impl<'sess> AttributeParser<'sess> {
                 cx.emit_lint_with_sess(
                     lint,
                     move |dcx, level, _| {
-                        InvalidTargetLint {
-                            name: name.to_string(),
+                        InvalidTarget {
+                            name,
                             target: target.plural_name(),
                             only: if only { "only " } else { "" },
                             applied: DiagArgValue::StrListSepByAnd(
                                 applied.iter().map(|i| Cow::Owned(i.to_string())).collect(),
                             ),
-                            attr_span,
+                            span: attr_span,
+                            previously_accepted: true,
                         }
                         .into_diag(dcx, level)
                     },
@@ -177,6 +177,7 @@ impl<'sess> AttributeParser<'sess> {
                     applied: DiagArgValue::StrListSepByAnd(
                         applied.into_iter().map(Cow::Owned).collect(),
                     ),
+                    previously_accepted: false,
                 });
             }
         }