patch.diff

diff --git a/compiler/rustc_codegen_cranelift/src/driver/aot.rs b/compiler/rustc_codegen_cranelift/src/driver/aot.rs
index 05457ce15e9..8cdbbf4f8fe 100644
--- a/compiler/rustc_codegen_cranelift/src/driver/aot.rs
+++ b/compiler/rustc_codegen_cranelift/src/driver/aot.rs
@@ -66,7 +66,9 @@ fn emit_module(
     let work_product = if backend_config.disable_incr_cache {
         None
     } else {
-        rustc_incremental::copy_cgu_workproduct_to_incr_comp_cache_dir(tcx.sess, &name, &tmp_file)
+        rustc_incremental::copy_cgu_workproduct_to_incr_comp_cache_dir(
+            tcx.sess, &name, &tmp_file, None,
+        )
     };
 
     ModuleCodegenResult(
@@ -82,7 +84,8 @@ fn reuse_workproduct_for_cgu(
 ) -> CompiledModule {
     let work_product = cgu.previous_work_product(tcx);
     let obj_out = tcx.output_filenames(()).temp_path(OutputType::Object, Some(cgu.name().as_str()));
-    let source_file = rustc_incremental::in_incr_comp_dir_sess(&tcx.sess, &work_product.saved_file);
+    let source_file =
+        rustc_incremental::in_incr_comp_dir_sess(&tcx.sess, &work_product.saved_object_file);
     if let Err(err) = rustc_fs_util::link_or_copy(&source_file, &obj_out) {
         tcx.sess.err(&format!(
             "unable to copy {} to {}: {}",
diff --git a/compiler/rustc_codegen_ssa/src/back/write.rs b/compiler/rustc_codegen_ssa/src/back/write.rs
index 632f07c5c2d..251d3b20a19 100644
--- a/compiler/rustc_codegen_ssa/src/back/write.rs
+++ b/compiler/rustc_codegen_ssa/src/back/write.rs
@@ -494,10 +494,13 @@ fn copy_all_cgu_workproducts_to_incr_comp_cache_dir(
     let _timer = sess.timer("copy_all_cgu_workproducts_to_incr_comp_cache_dir");
 
     for module in compiled_modules.modules.iter().filter(|m| m.kind == ModuleKind::Regular) {
-        if let Some(path) = &module.object {
-            if let Some((id, product)) =
-                copy_cgu_workproduct_to_incr_comp_cache_dir(sess, &module.name, path)
-            {
+        if let Some(object_file_path) = &module.object {
+            if let Some((id, product)) = copy_cgu_workproduct_to_incr_comp_cache_dir(
+                sess,
+                &module.name,
+                object_file_path,
+                module.dwarf_object.as_deref(),
+            ) {
                 work_products.insert(id, product);
             }
         }
@@ -856,29 +859,50 @@ fn execute_copy_from_cache_work_item<B: ExtraBackendMethods>(
     assert!(module_config.emit_obj != EmitObj::None);
 
     let incr_comp_session_dir = cgcx.incr_comp_session_dir.as_ref().unwrap();
-    let obj_out = cgcx.output_filenames.temp_path(OutputType::Object, Some(&module.name));
-    let source_file = in_incr_comp_dir(&incr_comp_session_dir, &module.source.saved_file);
-    debug!(
-        "copying pre-existing module `{}` from {:?} to {}",
-        module.name,
-        source_file,
-        obj_out.display()
+
+    let load_from_incr_comp_dir = |output_path: PathBuf, saved_path: &str| {
+        let source_file = in_incr_comp_dir(&incr_comp_session_dir, saved_path);
+        debug!(
+            "copying pre-existing module `{}` from {:?} to {}",
+            module.name,
+            source_file,
+            output_path.display()
+        );
+        match link_or_copy(&source_file, &output_path) {
+            Ok(_) => Some(output_path),
+            Err(err) => {
+                let diag_handler = cgcx.create_diag_handler();
+                diag_handler.err(&format!(
+                    "unable to copy {} to {}: {}",
+                    source_file.display(),
+                    output_path.display(),
+                    err
+                ));
+                None
+            }
+        }
+    };
+
+    let object = load_from_incr_comp_dir(
+        cgcx.output_filenames.temp_path(OutputType::Object, Some(&module.name)),
+        &module.source.saved_object_file,
     );
-    if let Err(err) = link_or_copy(&source_file, &obj_out) {
-        let diag_handler = cgcx.create_diag_handler();
-        diag_handler.err(&format!(
-            "unable to copy {} to {}: {}",
-            source_file.display(),
-            obj_out.display(),
-            err
-        ));
-    }
+    let dwarf_object =
+        module.source.saved_dwarf_object_file.as_ref().and_then(|saved_dwarf_object_file| {
+            let dwarf_obj_out = cgcx
+                .output_filenames
+                .split_dwarf_path(cgcx.split_debuginfo, cgcx.split_dwarf_kind, Some(&module.name))
+                .expect(
+                    "saved dwarf object in work product but `split_dwarf_path` returned `None`",
+                );
+            load_from_incr_comp_dir(dwarf_obj_out, &saved_dwarf_object_file)
+        });
 
     WorkItemResult::Compiled(CompiledModule {
         name: module.name,
         kind: ModuleKind::Regular,
-        object: Some(obj_out),
-        dwarf_object: None,
+        object,
+        dwarf_object,
         bytecode: None,
     })
 }
diff --git a/compiler/rustc_incremental/src/persist/load.rs b/compiler/rustc_incremental/src/persist/load.rs
index 9c325faae80..85205051b07 100644
--- a/compiler/rustc_incremental/src/persist/load.rs
+++ b/compiler/rustc_incremental/src/persist/load.rs
@@ -162,8 +162,17 @@ pub fn load_dep_graph(sess: &Session) -> DepGraphFuture {
 
             for swp in work_products {
                 let mut all_files_exist = true;
-                let path = in_incr_comp_dir_sess(sess, &swp.work_product.saved_file);
-                if !path.exists() {
+                let object_file_exists =
+                    in_incr_comp_dir_sess(sess, &swp.work_product.saved_object_file).exists();
+                let dwarf_object_file_exists = swp
+                    .work_product
+                    .saved_dwarf_object_file
+                    .as_ref()
+                    .map(|saved_dwarf_object_file| {
+                        in_incr_comp_dir_sess(sess, saved_dwarf_object_file).exists()
+                    })
+                    .unwrap_or(true);
+                if !object_file_exists || !dwarf_object_file_exists {
                     all_files_exist = false;
 
                     if sess.opts.debugging_opts.incremental_info {
diff --git a/compiler/rustc_incremental/src/persist/save.rs b/compiler/rustc_incremental/src/persist/save.rs
index 79836d66011..f16a528d0f8 100644
--- a/compiler/rustc_incremental/src/persist/save.rs
+++ b/compiler/rustc_incremental/src/persist/save.rs
@@ -108,7 +108,13 @@ pub fn save_work_product_index(
     for (id, wp) in previous_work_products.iter() {
         if !new_work_products.contains_key(id) {
             work_product::delete_workproduct_files(sess, wp);
-            debug_assert!(!in_incr_comp_dir_sess(sess, &wp.saved_file).exists());
+            debug_assert!(!in_incr_comp_dir_sess(sess, &wp.saved_object_file).exists());
+            debug_assert!(
+                !wp.saved_dwarf_object_file
+                    .as_ref()
+                    .map(|file| !in_incr_comp_dir_sess(sess, file).exists())
+                    .unwrap_or(false)
+            );
         }
     }
 
@@ -116,9 +122,17 @@ pub fn save_work_product_index(
     debug_assert!({
         new_work_products
             .iter()
-            .map(|(_, wp)| in_incr_comp_dir_sess(sess, &wp.saved_file))
+            .map(|(_, wp)| in_incr_comp_dir_sess(sess, &wp.saved_object_file))
             .all(|path| path.exists())
     });
+    debug_assert!({
+        new_work_products
+            .iter()
+            .map(|(_, wp)| {
+                wp.saved_dwarf_object_file.as_ref().map(|path| in_incr_comp_dir_sess(sess, path))
+            })
+            .all(|path| path.map(|path| path.exists()).unwrap_or(true))
+    });
 }
 
 fn encode_work_product_index(
diff --git a/compiler/rustc_incremental/src/persist/work_product.rs b/compiler/rustc_incremental/src/persist/work_product.rs
index 4789c0f581f..642a1a6843d 100644
--- a/compiler/rustc_incremental/src/persist/work_product.rs
+++ b/compiler/rustc_incremental/src/persist/work_product.rs
@@ -13,27 +13,35 @@
 pub fn copy_cgu_workproduct_to_incr_comp_cache_dir(
     sess: &Session,
     cgu_name: &str,
-    path: &Path,
+    object_file_path: &Path,
+    dwarf_object_file_path: Option<&Path>,
 ) -> Option<(WorkProductId, WorkProduct)> {
-    debug!("copy_cgu_workproduct_to_incr_comp_cache_dir({:?},{:?})", cgu_name, path);
+    debug!(?cgu_name, ?object_file_path, ?dwarf_object_file_path);
     sess.opts.incremental.as_ref()?;
 
-    let file_name = format!("{}.o", cgu_name);
-    let path_in_incr_dir = in_incr_comp_dir_sess(sess, &file_name);
-    let saved_file = match link_or_copy(path, &path_in_incr_dir) {
-        Ok(_) => file_name,
-        Err(err) => {
-            sess.warn(&format!(
-                "error copying object file `{}` to incremental directory as `{}`: {}",
-                path.display(),
-                path_in_incr_dir.display(),
-                err
-            ));
-            return None;
+    let save_in_incr_comp_dir = |path: &Path, ext: &'static str| {
+        let file_name = format!("{cgu_name}.{ext}");
+        let path_in_incr_dir = in_incr_comp_dir_sess(sess, &file_name);
+        match link_or_copy(path, &path_in_incr_dir) {
+            Ok(_) => Some(file_name),
+            Err(err) => {
+                sess.warn(&format!(
+                    "error copying object file `{}` to incremental directory as `{}`: {}",
+                    path.display(),
+                    path_in_incr_dir.display(),
+                    err
+                ));
+                return None;
+            }
         }
     };
 
-    let work_product = WorkProduct { cgu_name: cgu_name.to_string(), saved_file };
+    let saved_object_file = save_in_incr_comp_dir(object_file_path, "o")?;
+    let saved_dwarf_object_file =
+        dwarf_object_file_path.and_then(|path| save_in_incr_comp_dir(path, "dwo"));
+
+    let work_product =
+        WorkProduct { cgu_name: cgu_name.to_string(), saved_object_file, saved_dwarf_object_file };
 
     let work_product_id = WorkProductId::from_cgu_name(cgu_name);
     Some((work_product_id, work_product))
@@ -41,15 +49,22 @@ pub fn copy_cgu_workproduct_to_incr_comp_cache_dir(
 
 /// Removes files for a given work product.
 pub fn delete_workproduct_files(sess: &Session, work_product: &WorkProduct) {
-    let path = in_incr_comp_dir_sess(sess, &work_product.saved_file);
-    match std_fs::remove_file(&path) {
-        Ok(()) => {}
-        Err(err) => {
-            sess.warn(&format!(
-                "file-system error deleting outdated file `{}`: {}",
-                path.display(),
-                err
-            ));
+    let delete_workproduct_file = |path: &str| {
+        let path = in_incr_comp_dir_sess(sess, path);
+        match std_fs::remove_file(&path) {
+            Ok(()) => {}
+            Err(err) => {
+                sess.warn(&format!(
+                    "file-system error deleting outdated file `{}`: {}",
+                    path.display(),
+                    err
+                ));
+            }
         }
+    };
+
+    delete_workproduct_file(&work_product.saved_object_file);
+    if let Some(saved_dwarf_object_file) = &work_product.saved_dwarf_object_file {
+        delete_workproduct_file(saved_dwarf_object_file);
     }
 }
diff --git a/compiler/rustc_query_system/src/dep_graph/graph.rs b/compiler/rustc_query_system/src/dep_graph/graph.rs
index 341cf8f827b..8fcde1f9b98 100644
--- a/compiler/rustc_query_system/src/dep_graph/graph.rs
+++ b/compiler/rustc_query_system/src/dep_graph/graph.rs
@@ -886,8 +886,10 @@ pub(crate) fn next_virtual_depnode_index(&self) -> DepNodeIndex {
 #[derive(Clone, Debug, Encodable, Decodable)]
 pub struct WorkProduct {
     pub cgu_name: String,
-    /// Saved file associated with this CGU.
-    pub saved_file: String,
+    /// Saved `.o` file associated with this CGU.
+    pub saved_object_file: String,
+    /// Saved `.dwo` file associated with this CGU.
+    pub saved_dwarf_object_file: Option<String>,
 }
 
 // Index type for `DepNodeData`'s edges.