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 https://github.com/rust-lang/rust/pull/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" ( https://github.com/rust-lang/rust/issues/113349 )

r? SparrowLii

`@rustbot` label WG-compiler-parallel

examples/rustc-driver-example.rs

@@ -15,9 +15,9 @@ extern crate rustc_span;
 
 use std::io;
 use std::path::Path;
+use std::sync::Arc;
 
 use rustc_ast_pretty::pprust::item_to_string;
-use rustc_data_structures::sync::Lrc;
 use rustc_driver::{Compilation, run_compiler};
 use rustc_interface::interface::{Compiler, Config};
 use rustc_middle::ty::TyCtxt;
@@ -43,7 +43,7 @@ fn main() {
         }
     }
 
-    fn read_binary_file(&self, _path: &Path) -> io::Result<Lrc<[u8]>> {
+    fn read_binary_file(&self, _path: &Path) -> io::Result<Arc<[u8]>> {
         Err(io::Error::other("oops"))
     }
 }

examples/rustc-driver-interacting-with-the-ast.rs

@@ -15,9 +15,9 @@ extern crate rustc_span;
 
 use std::io;
 use std::path::Path;
+use std::sync::Arc;
 
 use rustc_ast_pretty::pprust::item_to_string;
-use rustc_data_structures::sync::Lrc;
 use rustc_driver::{Compilation, run_compiler};
 use rustc_interface::interface::{Compiler, Config};
 use rustc_middle::ty::TyCtxt;
@@ -43,7 +43,7 @@ fn main() {
         }
     }
 
-    fn read_binary_file(&self, _path: &Path) -> io::Result<Lrc<[u8]>> {
+    fn read_binary_file(&self, _path: &Path) -> io::Result<Arc<[u8]>> {
         Err(io::Error::other("oops"))
     }
 }

src/diagnostics/lintstore.md

@@ -54,7 +54,7 @@ Lints are registered via the [`LintStore::register_lint`] function. This should
 happen just once for any lint, or an ICE will occur.
 
 Once the registration is complete, we "freeze" the lint store by placing it in
-an `Lrc`.
+an `Arc`.
 
 Lint passes are registered separately into one of the categories
 (pre-expansion, early, late, late module). Passes are registered as a closure

src/parallel-rustc.md

@@ -46,7 +46,6 @@ are implemented differently depending on whether `parallel-compiler` is true.
 
 | data structure                   | parallel                                            | non-parallel |
 | -------------------------------- | --------------------------------------------------- | ------------ |
-| Lrc                              | std::sync::Arc | std::rc::Rc |
 | Weak                             | std::sync::Weak                                     | std::rc::Weak |
 | Atomic{Bool}/{Usize}/{U32}/{U64} | std::sync::atomic::Atomic{Bool}/{Usize}/{U32}/{U64} | (std::cell::Cell<bool/usize/u32/u64>) |
 | OnceCell                         | std::sync::OnceLock                                 | std::cell::OnceCell |