Batch symbol interner lookups

compiler/rustc_ast/src/ast.rs

@@ -31,7 +31,9 @@ use rustc_data_structures::tagged_ptr::Tag;
 use rustc_macros::{Decodable, Encodable, HashStable_Generic, Walkable};
 pub use rustc_span::AttrId;
 use rustc_span::source_map::{Spanned, respan};
-use rustc_span::{ByteSymbol, DUMMY_SP, ErrorGuaranteed, Ident, Span, Symbol, kw, sym};
+use rustc_span::{
+    ByteSymbol, DUMMY_SP, ErrorGuaranteed, Ident, Span, Symbol, kw, sym, with_session_globals,
+};
 use thin_vec::{ThinVec, thin_vec};
 
 pub use crate::format::*;
@@ -170,16 +172,18 @@ pub fn join_path_syms(path: impl IntoIterator<Item = impl Borrow<Symbol>>) -> St
     let mut s = String::with_capacity(len_hint * 8);
 
     let first_sym = *iter.next().unwrap().borrow();
-    if first_sym != kw::PathRoot {
-        s.push_str(first_sym.as_str());
-    }
-    for sym in iter {
-        let sym = *sym.borrow();
-        debug_assert_ne!(sym, kw::PathRoot);
-        s.push_str("::");
-        s.push_str(sym.as_str());
-    }
-    s
+    with_session_globals(|globals| {
+        if first_sym != kw::PathRoot {
+            s.push_str(first_sym.get_str_from_session_globals(globals));
+        }
+        for sym in iter {
+            let sym = *sym.borrow();
+            debug_assert_ne!(sym, kw::PathRoot);
+            s.push_str("::");
+            s.push_str(sym.get_str_from_session_globals(globals));
+        }
+        s
+    })
 }
 
 /// Like `join_path_syms`, but for `Ident`s. This function is necessary because

compiler/rustc_ast/src/token.rs

@@ -8,7 +8,7 @@ pub use TokenKind::*;
 use rustc_macros::{Decodable, Encodable, HashStable_Generic};
 use rustc_span::edition::Edition;
 use rustc_span::symbol::IdentPrintMode;
-use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span, kw, sym};
+use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span, kw, sym, with_session_globals};
 #[allow(clippy::useless_attribute)] // FIXME: following use of `hidden_glob_reexports` incorrectly triggers `useless_attribute` lint.
 #[allow(hidden_glob_reexports)]
 use rustc_span::{Ident, Symbol};
@@ -927,8 +927,12 @@ impl Token {
         self.is_keyword(kw)
             || (case == Case::Insensitive
                 && self.is_non_raw_ident_where(|id| {
-                    // Do an ASCII case-insensitive match, because all keywords are ASCII.
-                    id.name.as_str().eq_ignore_ascii_case(kw.as_str())
+                    with_session_globals(|globals| {
+                        // Do an ASCII case-insensitive match, because all keywords are ASCII.
+                        id.name
+                            .get_str_from_session_globals(globals)
+                            .eq_ignore_ascii_case(kw.get_str_from_session_globals(globals))
+                    })
                 }))
     }
 

compiler/rustc_parse/src/parser/item.rs

@@ -15,7 +15,9 @@ use rustc_errors::{Applicability, PResult, StashKey, struct_span_code_err};
 use rustc_session::lint::builtin::VARARGS_WITHOUT_PATTERN;
 use rustc_span::edit_distance::edit_distance;
 use rustc_span::edition::Edition;
-use rustc_span::{DUMMY_SP, ErrorGuaranteed, Ident, Span, Symbol, kw, source_map, sym};
+use rustc_span::{
+    DUMMY_SP, ErrorGuaranteed, Ident, Span, Symbol, kw, source_map, sym, with_session_globals,
+};
 use thin_vec::{ThinVec, thin_vec};
 use tracing::debug;
 
@@ -2653,9 +2655,9 @@ impl<'a> Parser<'a> {
                                     && i.is_reserved()
                             )
                             || case == Case::Insensitive
-                                && t.is_non_raw_ident_where(|i| quals.iter().any(|exp| {
-                                    exp.kw.as_str() == i.name.as_str().to_lowercase()
-                                }))
+                                && with_session_globals(|globals| t.is_non_raw_ident_where(|i| quals.iter().any(|exp| {
+                                    exp.kw.get_str_from_session_globals(globals) == i.name.get_str_from_session_globals(globals).to_lowercase()
+                                })))
                         )
                         // Rule out `unsafe extern {`.
                         && !self.is_unsafe_foreign_mod()

compiler/rustc_span/src/symbol.rs

@@ -15,7 +15,7 @@ use rustc_data_structures::sync::Lock;
 use rustc_macros::{Decodable, Encodable, HashStable_Generic, symbols};
 
 use crate::edit_distance::find_best_match_for_name;
-use crate::{DUMMY_SP, Edition, Span, with_session_globals};
+use crate::{DUMMY_SP, Edition, SessionGlobals, Span, with_session_globals};
 
 #[cfg(test)]
 mod tests;
@@ -2830,6 +2830,13 @@ impl Symbol {
         })
     }
 
+    pub fn get_str_from_session_globals<'sess>(
+        &self,
+        session_globals: &'sess SessionGlobals,
+    ) -> &'sess str {
+        session_globals.symbol_interner.get_str(*self)
+    }
+
     pub fn as_u32(self) -> u32 {
         self.0.as_u32()
     }
@@ -2900,7 +2907,10 @@ impl StableCompare for Symbol {
     const CAN_USE_UNSTABLE_SORT: bool = true;
 
     fn stable_cmp(&self, other: &Self) -> std::cmp::Ordering {
-        self.as_str().cmp(other.as_str())
+        with_session_globals(|session_globals| {
+            self.get_str_from_session_globals(session_globals)
+                .cmp(other.get_str_from_session_globals(session_globals))
+        })
     }
 }