Remove unused attribute check for unparsed builtin attributes

Author: JonathanBrouwer

compiler/rustc_expand/src/errors.rs

@@ -603,21 +603,3 @@ pub(crate) struct TrailingMacro {
     pub is_trailing: bool,
     pub name: Ident,
 }
-
-#[derive(Diagnostic)]
-#[diag("unused attribute `{$attr_name}`")]
-pub(crate) struct UnusedBuiltinAttribute {
-    #[note(
-        "the built-in attribute `{$attr_name}` will be ignored, since it's applied to the macro invocation `{$macro_name}`"
-    )]
-    pub invoc_span: Span,
-    pub attr_name: Symbol,
-    pub macro_name: String,
-    #[suggestion(
-        "remove the attribute",
-        code = "",
-        applicability = "machine-applicable",
-        style = "tool-only"
-    )]
-    pub attr_span: Span,
-}

compiler/rustc_expand/src/expand.rs

@@ -15,7 +15,7 @@ use rustc_ast::{
 use rustc_ast_pretty::pprust;
 use rustc_attr_parsing::parser::AllowExprMetavar;
 use rustc_attr_parsing::{
-    AttributeParser, AttributeSafety, CFG_TEMPLATE, Early, EvalConfigResult, ShouldEmit,
+    AttributeParser, AttributeSafety, CFG_TEMPLATE, EvalConfigResult, ShouldEmit,
     eval_config_entry, parse_cfg, validate_attr,
 };
 use rustc_data_structures::flat_map_in_place::FlatMapInPlace;
@@ -30,7 +30,7 @@ use rustc_parse::parser::{
     RecoverColon, RecoverComma, Recovery, token_descr,
 };
 use rustc_session::Session;
-use rustc_session::lint::builtin::{UNUSED_ATTRIBUTES, UNUSED_DOC_COMMENTS};
+use rustc_session::lint::builtin::UNUSED_DOC_COMMENTS;
 use rustc_session::parse::feature_err;
 use rustc_span::hygiene::SyntaxContext;
 use rustc_span::{ErrorGuaranteed, FileName, Ident, LocalExpnId, Span, Symbol, sym};
@@ -2274,21 +2274,6 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
                     self.cx.current_expansion.lint_node_id,
                     crate::errors::MacroCallUnusedDocComment { span: attr.span },
                 );
-            } else if rustc_attr_parsing::is_builtin_attr(attr)
-                && !AttributeParser::<Early>::is_parsed_attribute(&attr.path())
-            {
-                let attr_name = attr.name().unwrap();
-                self.cx.sess.psess.buffer_lint(
-                    UNUSED_ATTRIBUTES,
-                    attr.span,
-                    self.cx.current_expansion.lint_node_id,
-                    crate::errors::UnusedBuiltinAttribute {
-                        attr_name,
-                        macro_name: pprust::path_to_string(&call.path),
-                        invoc_span: call.path.span,
-                        attr_span: attr.span,
-                    },
-                );
             }
         }
     }

compiler/rustc_expand/src/module.rs

@@ -186,6 +186,7 @@ pub(crate) fn mod_file_path_from_attr(
     attrs: &[Attribute],
     dir_path: &Path,
 ) -> Option<PathBuf> {
+    // FIXME(154781) use a parsed attribute here
     // Extract path string from first `#[path = "path_string"]` attribute.
     let first_path = attrs.iter().find(|at| at.has_name(sym::path))?;
     let Some(path_sym) = first_path.value_str() else {