Rollup merge of #98901 - davidtwco:split-dwarf-incr-workproduct, r=michaelwoerister

incr: cache dwarf objects in work products

Cache DWARF objects alongside object files in work products when those exist so that DWARF object files are available for thorin in packed mode in incremental scenarios.

r? `@michaelwoerister`

2 files changed, 70 insertions, 38 deletions

diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs
index 72aa790c363..960e98243ac 100644
--- a/compiler/rustc_codegen_ssa/src/back/link.rs
+++ b/compiler/rustc_codegen_ssa/src/back/link.rs
@@ -151,11 +151,23 @@ pub fn link_binary<'a, B: ArchiveBuilder<'a>>(
             return;
         }
 
-        let remove_temps_from_module = |module: &CompiledModule| {
-            if let Some(ref obj) = module.object {
-                ensure_removed(sess.diagnostic(), obj);
-            }
-        };
+        let maybe_remove_temps_from_module =
+            |preserve_objects: bool, preserve_dwarf_objects: bool, module: &CompiledModule| {
+                if !preserve_objects {
+                    if let Some(ref obj) = module.object {
+                        ensure_removed(sess.diagnostic(), obj);
+                    }
+                }
+
+                if !preserve_dwarf_objects {
+                    if let Some(ref dwo_obj) = module.dwarf_object {
+                        ensure_removed(sess.diagnostic(), dwo_obj);
+                    }
+                }
+            };
+
+        let remove_temps_from_module =
+            |module: &CompiledModule| maybe_remove_temps_from_module(false, false, module);
 
         // Otherwise, always remove the metadata and allocator module temporaries.
         if let Some(ref metadata_module) = codegen_results.metadata_module {
@@ -177,15 +189,7 @@ pub fn link_binary<'a, B: ArchiveBuilder<'a>>(
         debug!(?preserve_objects, ?preserve_dwarf_objects);
 
         for module in &codegen_results.modules {
-            if !preserve_objects {
-                remove_temps_from_module(module);
-            }
-
-            if !preserve_dwarf_objects {
-                if let Some(ref obj) = module.dwarf_object {
-                    ensure_removed(sess.diagnostic(), obj);
-                }
-            }
+            maybe_remove_temps_from_module(preserve_objects, preserve_dwarf_objects, module);
         }
     });
 
@@ -649,6 +653,7 @@ fn link_dwarf_object<'a>(
             sess.struct_err("linking dwarf objects with thorin failed")
                 .note(&format!("{:?}", e))
                 .emit();
+            sess.abort_if_errors();
         }
     }
 }
diff --git a/compiler/rustc_codegen_ssa/src/back/write.rs b/compiler/rustc_codegen_ssa/src/back/write.rs
index 632f07c5c2d..f4a5cac872e 100644
--- a/compiler/rustc_codegen_ssa/src/back/write.rs
+++ b/compiler/rustc_codegen_ssa/src/back/write.rs
@@ -494,12 +494,18 @@ 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)
-            {
-                work_products.insert(id, product);
-            }
+        let mut files = Vec::new();
+        if let Some(object_file_path) = &module.object {
+            files.push(("o", object_file_path.as_path()));
+        }
+        if let Some(dwarf_object_file_path) = &module.dwarf_object {
+            files.push(("dwo", dwarf_object_file_path.as_path()));
+        }
+
+        if let Some((id, product)) =
+            copy_cgu_workproduct_to_incr_comp_cache_dir(sess, &module.name, files.as_slice())
+        {
+            work_products.insert(id, product);
         }
     }
 
@@ -856,29 +862,50 @@ 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_files.get("o").expect("no saved object file in work product"),
     );
-    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_files.get("dwo").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,
     })
 }