Port #[cfg] to the new attribute parsing infrastructure

compiler/rustc_ast/src/expand/mod.rs

@@ -1,24 +1,7 @@
 //! Definitions shared by macros / syntax extensions and e.g. `rustc_middle`.
 
 use rustc_macros::{Decodable, Encodable, HashStable_Generic};
-use rustc_span::Ident;
-use rustc_span::def_id::DefId;
-
-use crate::MetaItem;
 
 pub mod allocator;
 pub mod autodiff_attrs;
 pub mod typetree;
-
-#[derive(Debug, Clone, Encodable, Decodable, HashStable_Generic)]
-pub struct StrippedCfgItem<ModId = DefId> {
-    pub parent_module: ModId,
-    pub ident: Ident,
-    pub cfg: MetaItem,
-}
-
-impl<ModId> StrippedCfgItem<ModId> {
-    pub fn map_mod_id<New>(self, f: impl FnOnce(ModId) -> New) -> StrippedCfgItem<New> {
-        StrippedCfgItem { parent_module: f(self.parent_module), ident: self.ident, cfg: self.cfg }
-    }
-}

compiler/rustc_ast_lowering/src/lib.rs

@@ -42,7 +42,7 @@ use std::sync::Arc;
 
 use rustc_ast::node_id::NodeMap;
 use rustc_ast::{self as ast, *};
-use rustc_attr_parsing::{AttributeParser, OmitDoc};
+use rustc_attr_parsing::{AttributeParser, Late, OmitDoc};
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::sorted_map::SortedMap;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
@@ -192,7 +192,12 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             // interact with `gen`/`async gen` blocks
             allow_async_iterator: [sym::gen_future, sym::async_iterator].into(),
 
-            attribute_parser: AttributeParser::new(tcx.sess, tcx.features(), registered_tools),
+            attribute_parser: AttributeParser::new(
+                tcx.sess,
+                tcx.features(),
+                registered_tools,
+                Late,
+            ),
             delayed_lints: Vec::new(),
         }
     }

compiler/rustc_attr_data_structures/src/attributes.rs

@@ -3,7 +3,7 @@ use rustc_ast::token::CommentKind;
 use rustc_ast::{self as ast, AttrStyle};
 use rustc_macros::{Decodable, Encodable, HashStable_Generic, PrintAttribute};
 use rustc_span::hygiene::Transparency;
-use rustc_span::{Span, Symbol};
+use rustc_span::{Ident, Span, Symbol};
 use thin_vec::ThinVec;
 
 use crate::{DefaultBodyStability, PartialConstStability, PrintAttribute, RustcVersion, Stability};
@@ -69,6 +69,7 @@ pub enum ReprAttr {
     ReprAlign(Align),
 }
 pub use ReprAttr::*;
+use rustc_span::def_id::DefId;
 
 pub enum TransparencyError {
     UnknownTransparency(Symbol, Span),
@@ -140,6 +141,30 @@ pub enum UsedBy {
     Linker,
 }
 
+#[derive(Debug, Clone, Encodable, Decodable, HashStable_Generic)]
+pub struct StrippedCfgItem<ModId = DefId> {
+    pub parent_module: ModId,
+    pub ident: Ident,
+    pub cfg: (CfgEntry, Span),
+}
+
+impl<ModId> StrippedCfgItem<ModId> {
+    pub fn map_mod_id<New>(self, f: impl FnOnce(ModId) -> New) -> StrippedCfgItem<New> {
+        StrippedCfgItem { parent_module: f(self.parent_module), ident: self.ident, cfg: self.cfg }
+    }
+}
+
+#[derive(Encodable, Decodable, Clone, Debug, PartialEq, Eq, Hash)]
+#[derive(HashStable_Generic, PrintAttribute)]
+pub enum CfgEntry {
+    All(ThinVec<CfgEntry>, Span),
+    Any(ThinVec<CfgEntry>, Span),
+    Not(Box<CfgEntry>, Span),
+    Bool(bool, Span),
+    NameValue { name: Symbol, name_span: Span, value: Option<(Symbol, Span)>, span: Span },
+    Version(Option<RustcVersion>, Span),
+}
+
 /// Represents parsed *built-in* inert attributes.
 ///
 /// ## Overview
@@ -211,6 +236,9 @@ pub enum AttributeKind {
         span: Span,
     },
 
+    /// Represents `#[cfg]`.
+    Cfg(CfgEntry, Span),
+
     /// Represents `#[cold]`.
     Cold(Span),
 

compiler/rustc_attr_data_structures/src/encode_cross_crate.rs

@@ -18,6 +18,7 @@ impl AttributeKind {
             AllowInternalUnstable(..) => Yes,
             AsPtr(..) => Yes,
             BodyStability { .. } => No,
+            Cfg { .. } => Yes,
             Cold(..) => No,
             Confusables { .. } => Yes,
             ConstContinue(..) => No,