Remove an LTO dependent cgu_reuse_tracker.set_actual_reuse call

compiler/rustc_codegen_llvm/src/back/lto.rs

@@ -19,7 +19,6 @@
 use rustc_middle::bug;
 use rustc_middle::dep_graph::WorkProduct;
 use rustc_middle::middle::exported_symbols::{SymbolExportInfo, SymbolExportLevel};
-use rustc_session::cgu_reuse_tracker::CguReuse;
 use rustc_session::config::{self, CrateType, Lto};
 
 use std::ffi::{CStr, CString};
@@ -584,7 +583,6 @@ fn thin_lto(
                     copy_jobs.push(work_product);
                     info!(" - {}: re-used", module_name);
                     assert!(cgcx.incr_comp_session_dir.is_some());
-                    cgcx.cgu_reuse_tracker.set_actual_reuse(module_name, CguReuse::PostLto);
                     continue;
                 }
             }

compiler/rustc_codegen_ssa/src/back/write.rs

@@ -26,7 +26,6 @@
 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
 use rustc_middle::middle::exported_symbols::SymbolExportInfo;
 use rustc_middle::ty::TyCtxt;
-use rustc_session::cgu_reuse_tracker::CguReuseTracker;
 use rustc_session::config::{self, CrateType, Lto, OutFileName, OutputFilenames, OutputType};
 use rustc_session::config::{Passes, SwitchWithOptPath};
 use rustc_session::Session;
@@ -366,8 +365,6 @@ pub struct CodegenContext<B: WriteBackendMethods> {
     /// The incremental compilation session directory, or None if we are not
     /// compiling incrementally
     pub incr_comp_session_dir: Option<PathBuf>,
-    /// Used to update CGU re-use information during the thinlto phase.
-    pub cgu_reuse_tracker: CguReuseTracker,
     /// Channel back to the main control thread to send messages to
     pub coordinator_send: Sender<Box<dyn Any + Send>>,
 }
@@ -1119,7 +1116,6 @@ fn start_executing_work<B: ExtraBackendMethods>(
         remark: sess.opts.cg.remark.clone(),
         remark_dir,
         incr_comp_session_dir: sess.incr_comp_session_dir_opt().map(|r| r.clone()),
-        cgu_reuse_tracker: sess.cgu_reuse_tracker.clone(),
         coordinator_send,
         expanded_args: tcx.sess.expanded_args.clone(),
         diag_emitter: shared_emitter.clone(),

compiler/rustc_session/src/cgu_reuse_tracker.rs

@@ -75,13 +75,7 @@ pub fn set_actual_reuse(&self, cgu_name: &str, kind: CguReuse) {
             debug!("set_actual_reuse({cgu_name:?}, {kind:?})");
 
             let prev_reuse = data.lock().unwrap().actual_reuse.insert(cgu_name.to_string(), kind);
-
-            if let Some(prev_reuse) = prev_reuse {
-                // The only time it is legal to overwrite reuse state is when
-                // we discover during ThinLTO that we can actually reuse the
-                // post-LTO version of a CGU.
-                assert_eq!(prev_reuse, CguReuse::PreLto);
-            }
+            assert!(prev_reuse.is_none());
         }
     }