Auto merge of #107586 - SparrowLii:parallel-query, r=cjgillot

Introduce `DynSend` and `DynSync` auto trait for parallel compiler

part of parallel-rustc #101566

This PR introduces `DynSend / DynSync` trait and `FromDyn / IntoDyn` structure in rustc_data_structure::marker. `FromDyn` can dynamically check data structures for thread safety when switching to parallel environments (such as calling `par_for_each_in`). This happens only when `-Z threads > 1` so it doesn't affect single-threaded mode's compile efficiency.

r? `@cjgillot`

1 files changed, 5 insertions, 3 deletions

diff --git a/compiler/rustc_span/src/source_map.rs b/compiler/rustc_span/src/source_map.rs
index 1294a8b8e6b..8238a16969d 100644
--- a/compiler/rustc_span/src/source_map.rs
+++ b/compiler/rustc_span/src/source_map.rs
@@ -14,7 +14,9 @@ pub use crate::*;
 
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::stable_hasher::{Hash128, Hash64, StableHasher};
-use rustc_data_structures::sync::{AtomicU32, Lrc, MappedReadGuard, ReadGuard, RwLock};
+use rustc_data_structures::sync::{
+    AtomicU32, IntoDynSyncSend, Lrc, MappedReadGuard, ReadGuard, RwLock,
+};
 use std::cmp;
 use std::hash::Hash;
 use std::path::{self, Path, PathBuf};
@@ -176,7 +178,7 @@ pub struct SourceMap {
     used_address_space: AtomicU32,
 
     files: RwLock<SourceMapFiles>,
-    file_loader: Box<dyn FileLoader + Sync + Send>,
+    file_loader: IntoDynSyncSend<Box<dyn FileLoader + Sync + Send>>,
     // This is used to apply the file path remapping as specified via
     // `--remap-path-prefix` to all `SourceFile`s allocated within this `SourceMap`.
     path_mapping: FilePathMapping,
@@ -202,7 +204,7 @@ impl SourceMap {
         SourceMap {
             used_address_space: AtomicU32::new(0),
             files: Default::default(),
-            file_loader,
+            file_loader: IntoDynSyncSend(file_loader),
             path_mapping,
             hash_kind,
         }