Port #[macro_export] to the new attribute parsing infrastructure

Periodic1911 · Periodic1911 · commit bb6c5ddbe46c · 2025-07-13T00:21:44.000+02:00
diff --git a/compiler/rustc_attr_data_structures/src/attributes.rs b/compiler/rustc_attr_data_structures/src/attributes.rs
@@ -300,6 +300,9 @@ pub enum AttributeKind {
     /// Represents `#[loop_match]`.
     LoopMatch(Span),
 
+    /// Represents [`#[macro_export}`](https://doc.rust-lang.org/reference/macros-by-example.html#r-macro.decl.scope.path).
+    MacroExport { span: Span, local_inner_macros: bool },
+
     /// Represents `#[rustc_macro_transparency]`.
     MacroTransparency(Transparency),
 
diff --git a/compiler/rustc_attr_data_structures/src/encode_cross_crate.rs b/compiler/rustc_attr_data_structures/src/encode_cross_crate.rs
@@ -42,6 +42,7 @@ impl AttributeKind {
             LinkName { .. } => Yes,
             LinkSection { .. } => No,
             LoopMatch(..) => No,
+            MacroExport { .. } => Yes,
             MacroTransparency(..) => Yes,
             Marker(..) => No,
             MayDangle(..) => No,
diff --git a/compiler/rustc_attr_parsing/src/attributes/macro_attrs.rs b/compiler/rustc_attr_parsing/src/attributes/macro_attrs.rs
@@ -0,0 +1,45 @@
+use rustc_attr_data_structures::AttributeKind;
+use rustc_attr_data_structures::AttributeKind::MacroExport;
+use rustc_attr_data_structures::lints::AttributeLintKind;
+use rustc_feature::{AttributeTemplate, template};
+use rustc_span::{Symbol, sym};
+
+use crate::attributes::{AttributeOrder, OnDuplicate, SingleAttributeParser};
+use crate::context::{AcceptContext, Stage};
+use crate::parser::ArgParser;
+
+pub(crate) struct MacroExportParser;
+
+impl<S: Stage> SingleAttributeParser<S> for crate::attributes::macro_attrs::MacroExportParser {
+    const PATH: &[Symbol] = &[sym::macro_export];
+    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepOutermost;
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Warn;
+    const TEMPLATE: AttributeTemplate = template!(Word, List: "local_inner_macros");
+
+    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
+        let local_inner_macros = match args {
+            ArgParser::NoArgs => false,
+            ArgParser::List(list) => {
+                let Some(l) = list.single() else {
+                    cx.expected_single_argument(list.span);
+                    return None;
+                };
+                match l.meta_item().and_then(|i| i.path().word_sym()) {
+                    Some(sym::local_inner_macros) => true,
+                    _ => {
+                        cx.expected_specific_argument(l.span(), vec!["local_inner_macros"]);
+                        return None;
+                    }
+                }
+            }
+            ArgParser::NameValue(_) => {
+                let suggestions =
+                    <Self as SingleAttributeParser<S>>::TEMPLATE.suggestions(false, "macro_export");
+                let span = cx.attr_span;
+                cx.emit_lint(AttributeLintKind::IllFormedAttributeInput { suggestions }, span);
+                return None;
+            }
+        };
+        Some(MacroExport { span: cx.attr_span, local_inner_macros })
+    }
+}
diff --git a/compiler/rustc_attr_parsing/src/attributes/mod.rs b/compiler/rustc_attr_parsing/src/attributes/mod.rs
@@ -35,6 +35,7 @@ pub(crate) mod inline;
 pub(crate) mod link_attrs;
 pub(crate) mod lint_helpers;
 pub(crate) mod loop_match;
+pub(crate) mod macro_attrs;
 pub(crate) mod must_use;
 pub(crate) mod no_implicit_prelude;
 pub(crate) mod non_exhaustive;
diff --git a/compiler/rustc_attr_parsing/src/context.rs b/compiler/rustc_attr_parsing/src/context.rs
@@ -29,6 +29,7 @@ use crate::attributes::link_attrs::{
 };
 use crate::attributes::lint_helpers::{AsPtrParser, PassByValueParser, PubTransparentParser};
 use crate::attributes::loop_match::{ConstContinueParser, LoopMatchParser};
+use crate::attributes::macro_attrs::MacroExportParser;
 use crate::attributes::must_use::MustUseParser;
 use crate::attributes::no_implicit_prelude::NoImplicitPreludeParser;
 use crate::attributes::non_exhaustive::NonExhaustiveParser;
@@ -142,6 +143,7 @@ attribute_parsers!(
         Single<InlineParser>,
         Single<LinkNameParser>,
         Single<LinkSectionParser>,
+        Single<MacroExportParser>,
         Single<MustUseParser>,
         Single<OptimizeParser>,
         Single<PathAttributeParser>,
diff --git a/compiler/rustc_expand/src/base.rs b/compiler/rustc_expand/src/base.rs
@@ -892,9 +892,9 @@ impl SyntaxExtension {
         let allow_internal_unsafe =
             ast::attr::find_by_name(attrs, sym::allow_internal_unsafe).is_some();
 
-        let local_inner_macros = ast::attr::find_by_name(attrs, sym::macro_export)
-            .and_then(|macro_export| macro_export.meta_item_list())
-            .is_some_and(|l| ast::attr::list_contains_name(&l, sym::local_inner_macros));
+        let local_inner_macros =
+            *find_attr!(attrs, AttributeKind::MacroExport {local_inner_macros: l, ..} => l)
+                .unwrap_or(&false);
         let collapse_debuginfo = Self::get_collapse_debuginfo(sess, attrs, !is_local);
         tracing::debug!(?name, ?local_inner_macros, ?collapse_debuginfo, ?allow_internal_unsafe);
 
diff --git a/compiler/rustc_lint/src/non_local_def.rs b/compiler/rustc_lint/src/non_local_def.rs
@@ -1,11 +1,12 @@
+use rustc_attr_data_structures::{AttributeKind, find_attr};
 use rustc_errors::MultiSpan;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::intravisit::{self, Visitor, VisitorExt};
 use rustc_hir::{Body, HirId, Item, ItemKind, Node, Path, TyKind};
 use rustc_middle::ty::TyCtxt;
 use rustc_session::{declare_lint, impl_lint_pass};
 use rustc_span::def_id::{DefId, LOCAL_CRATE};
-use rustc_span::{ExpnKind, MacroKind, Span, kw, sym};
+use rustc_span::{ExpnKind, MacroKind, Span, kw};
 
 use crate::lints::{NonLocalDefinitionsCargoUpdateNote, NonLocalDefinitionsDiag};
 use crate::{LateContext, LateLintPass, LintContext, fluent_generated as fluent};
@@ -241,7 +242,10 @@ impl<'tcx> LateLintPass<'tcx> for NonLocalDefinitions {
                 )
             }
             ItemKind::Macro(_, _macro, MacroKind::Bang)
-                if cx.tcx.has_attr(item.owner_id.def_id, sym::macro_export) =>
+                if find_attr!(
+                    cx.tcx.get_all_attrs(item.owner_id.def_id),
+                    AttributeKind::MacroExport { .. }
+                ) =>
             {
                 cx.emit_span_lint(
                     NON_LOCAL_DEFINITIONS,
diff --git a/compiler/rustc_parse/src/validate_attr.rs b/compiler/rustc_parse/src/validate_attr.rs
@@ -302,6 +302,7 @@ pub fn check_builtin_meta_item(
                 | sym::cold
                 | sym::target_feature
                 | sym::rustc_allow_const_fn_unstable
+                | sym::macro_export
                 | sym::naked
                 | sym::no_mangle
                 | sym::non_exhaustive
diff --git a/compiler/rustc_passes/messages.ftl b/compiler/rustc_passes/messages.ftl
@@ -395,10 +395,6 @@ passes_invalid_attr_at_crate_level =
 passes_invalid_attr_at_crate_level_item =
     the inner attribute doesn't annotate this {$kind}
 
-passes_invalid_macro_export_arguments = invalid `#[macro_export]` argument
-
-passes_invalid_macro_export_arguments_too_many_items = `#[macro_export]` can only take 1 or 0 arguments
-
 passes_lang_item_fn = {$name ->
     [panic_impl] `#[panic_handler]`
     *[other] `{$name}` lang item
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
@@ -32,8 +32,8 @@ use rustc_middle::{bug, span_bug};
 use rustc_session::config::CrateType;
 use rustc_session::lint;
 use rustc_session::lint::builtin::{
-    CONFLICTING_REPR_HINTS, INVALID_DOC_ATTRIBUTES, INVALID_MACRO_EXPORT_ARGUMENTS,
-    UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES, UNUSED_ATTRIBUTES,
+    CONFLICTING_REPR_HINTS, INVALID_DOC_ATTRIBUTES, UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,
+    UNUSED_ATTRIBUTES,
 };
 use rustc_session::parse::feature_err;
 use rustc_span::edition::Edition;
@@ -242,6 +242,9 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     | AttributeKind::MacroTransparency(_)
                     | AttributeKind::Dummy,
                 ) => { /* do nothing  */ }
+                Attribute::Parsed(AttributeKind::MacroExport { span, .. }) => {
+                    self.check_macro_export(hir_id, *span, target)
+                }
                 Attribute::Parsed(AttributeKind::AsPtr(attr_span)) => {
                     self.check_applied_to_fn_or_method(hir_id, *attr_span, span, target)
                 }
@@ -331,7 +334,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                             self.check_macro_use(hir_id, attr, target)
                         }
                         [sym::path, ..] => self.check_generic_attr_unparsed(hir_id, attr, target, Target::Mod),
-                        [sym::macro_export, ..] => self.check_macro_export(hir_id, attr, target),
                         [sym::should_panic, ..] => {
                             self.check_generic_attr_unparsed(hir_id, attr, target, Target::Fn)
                         }
@@ -2294,32 +2296,14 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
         }
     }
 
-    fn check_macro_export(&self, hir_id: HirId, attr: &Attribute, target: Target) {
+    fn check_macro_export(&self, hir_id: HirId, attr_span: Span, target: Target) {
         if target != Target::MacroDef {
             self.tcx.emit_node_span_lint(
                 UNUSED_ATTRIBUTES,
                 hir_id,
-                attr.span(),
+                attr_span,
                 errors::MacroExport::Normal,
             );
-        } else if let Some(meta_item_list) = attr.meta_item_list()
-            && !meta_item_list.is_empty()
-        {
-            if meta_item_list.len() > 1 {
-                self.tcx.emit_node_span_lint(
-                    INVALID_MACRO_EXPORT_ARGUMENTS,
-                    hir_id,
-                    attr.span(),
-                    errors::MacroExport::TooManyItems,
-                );
-            } else if !meta_item_list[0].has_name(sym::local_inner_macros) {
-                self.tcx.emit_node_span_lint(
-                    INVALID_MACRO_EXPORT_ARGUMENTS,
-                    hir_id,
-                    meta_item_list[0].span(),
-                    errors::MacroExport::InvalidArgument,
-                );
-            }
         } else {
             // special case when `#[macro_export]` is applied to a macro 2.0
             let (_, macro_definition, _) = self.tcx.hir_node(hir_id).expect_item().expect_macro();
@@ -2329,7 +2313,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                 self.tcx.emit_node_span_lint(
                     UNUSED_ATTRIBUTES,
                     hir_id,
-                    attr.span(),
+                    attr_span,
                     errors::MacroExport::OnDeclMacro,
                 );
             }
@@ -2683,7 +2667,9 @@ impl<'tcx> Visitor<'tcx> for CheckAttrVisitor<'tcx> {
         // In the long run, the checks should be harmonized.
         if let ItemKind::Macro(_, macro_def, _) = item.kind {
             let def_id = item.owner_id.to_def_id();
-            if macro_def.macro_rules && !self.tcx.has_attr(def_id, sym::macro_export) {
+            if macro_def.macro_rules
+                && !find_attr!(self.tcx.get_all_attrs(def_id), AttributeKind::MacroExport { .. })
+            {
                 check_non_exported_macro_for_invalid_attrs(self.tcx, item);
             }
         }
@@ -2813,7 +2799,6 @@ fn check_invalid_crate_level_attr(tcx: TyCtxt<'_>, attrs: &[Attribute]) {
     // which were unsuccessfully resolved due to cannot determine
     // resolution for the attribute macro error.
     const ATTRS_TO_CHECK: &[Symbol] = &[
-        sym::macro_export,
         sym::automatically_derived,
         sym::rustc_main,
         sym::derive,
@@ -2837,6 +2822,8 @@ fn check_invalid_crate_level_attr(tcx: TyCtxt<'_>, attrs: &[Attribute]) {
             (*first_attr_span, sym::repr)
         } else if let Attribute::Parsed(AttributeKind::Path(.., span)) = attr {
             (*span, sym::path)
+        } else if let Attribute::Parsed(AttributeKind::MacroExport { span, .. }) = attr {
+            (*span, sym::macro_export)
         } else {
             continue;
         };
diff --git a/compiler/rustc_passes/src/errors.rs b/compiler/rustc_passes/src/errors.rs
@@ -769,12 +769,6 @@ pub(crate) enum MacroExport {
     #[diag(passes_macro_export_on_decl_macro)]
     #[note]
     OnDeclMacro,
-
-    #[diag(passes_invalid_macro_export_arguments)]
-    InvalidArgument,
-
-    #[diag(passes_invalid_macro_export_arguments_too_many_items)]
-    TooManyItems,
 }
 
 #[derive(Subdiagnostic)]
diff --git a/src/librustdoc/html/render/search_index.rs b/src/librustdoc/html/render/search_index.rs
@@ -4,6 +4,7 @@ use std::collections::hash_map::Entry;
 use std::collections::{BTreeMap, VecDeque};
 
 use encode::{bitmap_to_string, write_vlqhex_to_string};
+use rustc_attr_data_structures::{AttributeKind, find_attr};
 use rustc_data_structures::fx::{FxHashMap, FxIndexMap};
 use rustc_middle::ty::TyCtxt;
 use rustc_span::def_id::DefId;
@@ -408,16 +409,17 @@ pub(crate) fn build_index(
                     if fqp.last() != Some(&item.name) {
                         return None;
                     }
-                    let path =
-                        if item.ty == ItemType::Macro && tcx.has_attr(defid, sym::macro_export) {
-                            // `#[macro_export]` always exports to the crate root.
-                            tcx.crate_name(defid.krate).to_string()
-                        } else {
-                            if fqp.len() < 2 {
-                                return None;
-                            }
-                            join_with_double_colon(&fqp[..fqp.len() - 1])
-                        };
+                    let path = if item.ty == ItemType::Macro
+                        && find_attr!(tcx.get_all_attrs(defid), AttributeKind::MacroExport { .. })
+                    {
+                        // `#[macro_export]` always exports to the crate root.
+                        tcx.crate_name(defid.krate).to_string()
+                    } else {
+                        if fqp.len() < 2 {
+                            return None;
+                        }
+                        join_with_double_colon(&fqp[..fqp.len() - 1])
+                    };
                     if path == item.path {
                         return None;
                     }
diff --git a/src/librustdoc/passes/strip_hidden.rs b/src/librustdoc/passes/strip_hidden.rs
@@ -2,9 +2,9 @@
 
 use std::mem;
 
+use rustc_attr_data_structures::{AttributeKind, find_attr};
 use rustc_hir::def_id::{CRATE_DEF_ID, LocalDefId};
 use rustc_middle::ty::TyCtxt;
-use rustc_span::symbol::sym;
 use tracing::debug;
 
 use crate::clean::utils::inherits_doc_hidden;
@@ -114,7 +114,7 @@ impl DocFolder for Stripper<'_, '_> {
             // If the macro has the `#[macro_export]` attribute, it means it's accessible at the
             // crate level so it should be handled differently.
             clean::MacroItem(..) => {
-                i.attrs.other_attrs.iter().any(|attr| attr.has_name(sym::macro_export))
+                find_attr!(&i.attrs.other_attrs, AttributeKind::MacroExport { .. })
             }
             _ => false,
         };
diff --git a/src/librustdoc/visit_ast.rs b/src/librustdoc/visit_ast.rs
@@ -3,6 +3,7 @@
 
 use std::mem;
 
+use rustc_attr_data_structures::{AttributeKind, find_attr};
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
@@ -167,7 +168,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
             if !child.reexport_chain.is_empty()
                 && let Res::Def(DefKind::Macro(_), def_id) = child.res
                 && let Some(local_def_id) = def_id.as_local()
-                && self.cx.tcx.has_attr(def_id, sym::macro_export)
+                && find_attr!(self.cx.tcx.get_all_attrs(def_id), AttributeKind::MacroExport { .. })
                 && inserted.insert(def_id)
             {
                 let item = self.cx.tcx.hir_expect_item(local_def_id);
@@ -407,7 +408,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
             || match item.kind {
                 hir::ItemKind::Impl(..) => true,
                 hir::ItemKind::Macro(_, _, MacroKind::Bang) => {
-                    self.cx.tcx.has_attr(item.owner_id.def_id, sym::macro_export)
+                    find_attr!(self.cx.tcx.get_all_attrs(item.owner_id.def_id), AttributeKind::MacroExport{..})
                 }
                 _ => false,
             }
@@ -525,7 +526,8 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
 
                 let def_id = item.owner_id.to_def_id();
                 let is_macro_2_0 = !macro_def.macro_rules;
-                let nonexported = !tcx.has_attr(def_id, sym::macro_export);
+                let nonexported =
+                    !find_attr!(tcx.get_all_attrs(def_id), AttributeKind::MacroExport { .. });
 
                 if is_macro_2_0 || nonexported || self.inlining {
                     self.add_to_current_mod(item, renamed, import_id);
diff --git a/src/tools/clippy/clippy_lints/src/macro_metavars_in_unsafe.rs b/src/tools/clippy/clippy_lints/src/macro_metavars_in_unsafe.rs
@@ -8,7 +8,8 @@ use rustc_hir::{BlockCheckMode, Expr, ExprKind, HirId, Stmt, UnsafeSource};
 use rustc_lint::{LateContext, LateLintPass, Level, LintContext};
 use rustc_middle::lint::LevelAndSource;
 use rustc_session::impl_lint_pass;
-use rustc_span::{Span, SyntaxContext, sym};
+use rustc_span::{Span, SyntaxContext};
+use rustc_attr_data_structures::{find_attr, AttributeKind};
 use std::collections::BTreeMap;
 use std::collections::btree_map::Entry;
 
@@ -146,7 +147,8 @@ struct BodyVisitor<'a, 'tcx> {
 }
 
 fn is_public_macro(cx: &LateContext<'_>, def_id: LocalDefId) -> bool {
-    (cx.effective_visibilities.is_exported(def_id) || cx.tcx.has_attr(def_id, sym::macro_export))
+    ( cx.effective_visibilities.is_exported(def_id) ||
+        find_attr!(cx.tcx.get_all_attrs(def_id), AttributeKind::MacroExport{..}) )
         && !cx.tcx.is_doc_hidden(def_id)
 }
 
diff --git a/tests/ui/attributes/invalid_macro_export_argument.deny.stderr b/tests/ui/attributes/invalid_macro_export_argument.deny.stderr
diff --git a/tests/ui/attributes/invalid_macro_export_argument.rs b/tests/ui/attributes/invalid_macro_export_argument.rs
diff --git a/tests/ui/attributes/invalid_macro_export_argument.stderr b/tests/ui/attributes/invalid_macro_export_argument.stderr
diff --git a/tests/ui/attributes/malformed-attrs.rs b/tests/ui/attributes/malformed-attrs.rs
diff --git a/tests/ui/attributes/malformed-attrs.stderr b/tests/ui/attributes/malformed-attrs.stderr
diff --git a/tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs-error.stderr b/tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs-error.stderr
