XXX: RangeSet

Cargo.lock

@@ -2959,6 +2959,12 @@ dependencies = [
  "rand_core",
 ]
 
+[[package]]
+name = "rangemap"
+version = "1.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f60fcc7d6849342eff22c4350c8b9a989ee8ceabc4b481253e8946b9fe83d684"
+
 [[package]]
 name = "rayon"
 version = "1.10.0"
@@ -4166,6 +4172,7 @@ name = "rustc_parse"
 version = "0.0.0"
 dependencies = [
  "bitflags 2.6.0",
+ "rangemap",
  "rustc_ast",
  "rustc_ast_pretty",
  "rustc_data_structures",

compiler/rustc_parse/Cargo.toml

@@ -6,6 +6,7 @@ edition = "2021"
 [dependencies]
 # tidy-alphabetical-start
 bitflags = "2.4.1"
+rangemap = "1.5.1"
 rustc_ast = { path = "../rustc_ast" }
 rustc_ast_pretty = { path = "../rustc_ast_pretty" }
 rustc_data_structures = { path = "../rustc_data_structures" }

compiler/rustc_parse/src/parser/attr_wrapper.rs

@@ -270,9 +270,10 @@ impl<'a> Parser<'a> {
         // wrapping layer.
         let mut seen_indices = FxHashSet::default();
         for (i, attr) in ret.attrs().iter().enumerate() {
-            let is_unseen = self.capture_state.seen_attrs.insert(attr.id);
-            if !is_unseen {
+            if self.capture_state.seen_attrs.contains(&attr.id) {
                 seen_indices.insert(i);
+            } else {
+                self.capture_state.seen_attrs.insert(attr.id..attr.id + 1);
             }
         }
         let ret_attrs: Cow<'_, [Attribute]> =

compiler/rustc_parse/src/parser/mod.rs

@@ -20,6 +20,7 @@ pub(crate) use expr::ForbiddenLetReason;
 pub(crate) use item::FnParseMode;
 pub use pat::{CommaRecoveryMode, RecoverColon, RecoverComma};
 use path::PathStyle;
+use rangemap::RangeSet;
 use rustc_ast::ptr::P;
 use rustc_ast::token::{self, Delimiter, IdentIsRaw, Nonterminal, Token, TokenKind};
 use rustc_ast::tokenstream::{
@@ -32,7 +33,7 @@ use rustc_ast::{
     VisibilityKind, DUMMY_NODE_ID,
 };
 use rustc_ast_pretty::pprust;
-use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::{Applicability, Diag, FatalError, MultiSpan, PResult};
 use rustc_session::parse::ParseSess;
@@ -183,7 +184,7 @@ pub struct Parser<'a> {
 // This type is used a lot, e.g. it's cloned when matching many declarative macro rules with nonterminals. Make sure
 // it doesn't unintentionally get bigger.
 #[cfg(target_pointer_width = "64")]
-rustc_data_structures::static_assert_size!(Parser<'_>, 288);
+rustc_data_structures::static_assert_size!(Parser<'_>, 280);
 
 /// Stores span information about a closure.
 #[derive(Clone, Debug)]
@@ -261,7 +262,7 @@ struct CaptureState {
     capturing: Capturing,
     parser_replacements: Vec<ParserReplacement>,
     inner_attr_parser_ranges: FxHashMap<AttrId, ParserRange>,
-    seen_attrs: FxHashSet<AttrId>,
+    seen_attrs: RangeSet<AttrId>,
 }
 
 /// Iterator over a `TokenStream` that produces `Token`s. It's a bit odd that