Auto merge of #136471 - safinaskar:parallel, r=SparrowLii

tree-wide: parallel: Fully removed all `Lrc`, replaced with `Arc`

tree-wide: parallel: Fully removed all `Lrc`, replaced with `Arc`

This is continuation of #132282 .

I'm pretty sure I did everything right. In particular, I searched all occurrences of `Lrc` in submodules and made sure that they don't need replacement.

There are other possibilities, through.

We can define `enum Lrc<T> { Rc(Rc<T>), Arc(Arc<T>) }`. Or we can make `Lrc` a union and on every clone we can read from special thread-local variable. Or we can add a generic parameter to `Lrc` and, yes, this parameter will be everywhere across all codebase.

So, if you think we should take some alternative approach, then don't merge this PR. But if it is decided to stick with `Arc`, then, please, merge.

cc "Parallel Rustc Front-end" ( #113349 )

r? SparrowLii

`@rustbot` label WG-compiler-parallel

Author: bors

compiler/rustc_ast/src/ast.rs

@@ -19,6 +19,7 @@
 //! - [`UnOp`], [`BinOp`], and [`BinOpKind`]: Unary and binary operators.
 
 use std::borrow::Cow;
+use std::sync::Arc;
 use std::{cmp, fmt};
 
 pub use GenericArgs::*;
@@ -27,7 +28,6 @@ pub use rustc_ast_ir::{Movability, Mutability, Pinnedness};
 use rustc_data_structures::packed::Pu128;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::stack::ensure_sufficient_stack;
-use rustc_data_structures::sync::Lrc;
 use rustc_data_structures::tagged_ptr::Tag;
 use rustc_macros::{Decodable, Encodable, HashStable_Generic};
 pub use rustc_span::AttrId;
@@ -1611,7 +1611,7 @@ pub enum ExprKind {
     /// Added for optimization purposes to avoid the need to escape
     /// large binary blobs - should always behave like [`ExprKind::Lit`]
     /// with a `ByteStr` literal.
-    IncludedBytes(Lrc<[u8]>),
+    IncludedBytes(Arc<[u8]>),
 
     /// A `format_args!()` expression.
     FormatArgs(P<FormatArgs>),
@@ -1904,9 +1904,9 @@ pub enum LitKind {
     Str(Symbol, StrStyle),
     /// A byte string (`b"foo"`). Not stored as a symbol because it might be
     /// non-utf8, and symbols only allow utf8 strings.
-    ByteStr(Lrc<[u8]>, StrStyle),
+    ByteStr(Arc<[u8]>, StrStyle),
     /// A C String (`c"foo"`). Guaranteed to only have `\0` at the end.
-    CStr(Lrc<[u8]>, StrStyle),
+    CStr(Arc<[u8]>, StrStyle),
     /// A byte char (`b'f'`).
     Byte(u8),
     /// A character literal (`'a'`).

compiler/rustc_ast/src/mut_visit.rs

@@ -9,10 +9,10 @@
 
 use std::ops::DerefMut;
 use std::panic;
+use std::sync::Arc;
 
 use rustc_data_structures::flat_map_in_place::FlatMapInPlace;
 use rustc_data_structures::stack::ensure_sufficient_stack;
-use rustc_data_structures::sync::Lrc;
 use rustc_span::source_map::Spanned;
 use rustc_span::{Ident, Span};
 use smallvec::{Array, SmallVec, smallvec};
@@ -793,14 +793,14 @@ fn visit_tt<T: MutVisitor>(vis: &mut T, tt: &mut TokenTree) {
 // No `noop_` prefix because there isn't a corresponding method in `MutVisitor`.
 fn visit_tts<T: MutVisitor>(vis: &mut T, TokenStream(tts): &mut TokenStream) {
     if T::VISIT_TOKENS && !tts.is_empty() {
-        let tts = Lrc::make_mut(tts);
+        let tts = Arc::make_mut(tts);
         visit_vec(tts, |tree| visit_tt(vis, tree));
     }
 }
 
 fn visit_attr_tts<T: MutVisitor>(vis: &mut T, AttrTokenStream(tts): &mut AttrTokenStream) {
     if T::VISIT_TOKENS && !tts.is_empty() {
-        let tts = Lrc::make_mut(tts);
+        let tts = Arc::make_mut(tts);
         visit_vec(tts, |tree| visit_attr_tt(vis, tree));
     }
 }
@@ -840,7 +840,7 @@ pub fn visit_token<T: MutVisitor>(vis: &mut T, t: &mut Token) {
             vis.visit_ident(ident);
         }
         token::Interpolated(nt) => {
-            let nt = Lrc::make_mut(nt);
+            let nt = Arc::make_mut(nt);
             visit_nonterminal(vis, nt);
         }
         _ => {}