Various refactors to the incr comp workproduct handling

compiler/rustc_codegen_cranelift/src/driver/aot.rs

@@ -66,11 +66,7 @@ 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,
-            &Some(tmp_file.clone()),
-        )
+        rustc_incremental::copy_cgu_workproduct_to_incr_comp_cache_dir(tcx.sess, &name, &tmp_file)
     };
 
     ModuleCodegenResult(
@@ -84,29 +80,24 @@ fn reuse_workproduct_for_cgu(
     cgu: &CodegenUnit<'_>,
     work_products: &mut FxHashMap<WorkProductId, WorkProduct>,
 ) -> CompiledModule {
-    let mut object = None;
-    let work_product = cgu.work_product(tcx);
-    if let Some(saved_file) = &work_product.saved_file {
-        let obj_out =
-            tcx.output_filenames(()).temp_path(OutputType::Object, Some(cgu.name().as_str()));
-        object = Some(obj_out.clone());
-        let source_file = rustc_incremental::in_incr_comp_dir_sess(&tcx.sess, &saved_file);
-        if let Err(err) = rustc_fs_util::link_or_copy(&source_file, &obj_out) {
-            tcx.sess.err(&format!(
-                "unable to copy {} to {}: {}",
-                source_file.display(),
-                obj_out.display(),
-                err
-            ));
-        }
+    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);
+    if let Err(err) = rustc_fs_util::link_or_copy(&source_file, &obj_out) {
+        tcx.sess.err(&format!(
+            "unable to copy {} to {}: {}",
+            source_file.display(),
+            obj_out.display(),
+            err
+        ));
     }
 
     work_products.insert(cgu.work_product_id(), work_product);
 
     CompiledModule {
         name: cgu.name().to_string(),
         kind: ModuleKind::Regular,
-        object,
+        object: Some(obj_out),
         dwarf_object: None,
         bytecode: None,
     }

compiler/rustc_codegen_ssa/src/back/write.rs

@@ -494,12 +494,12 @@ 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) {
-        let path = module.object.as_ref().cloned();
-
-        if let Some((id, product)) =
-            copy_cgu_workproduct_to_incr_comp_cache_dir(sess, &module.name, &path)
-        {
-            work_products.insert(id, product);
+        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);
+            }
         }
     }
 
@@ -853,35 +853,31 @@ fn execute_copy_from_cache_work_item<B: ExtraBackendMethods>(
     module: CachedModuleCodegen,
     module_config: &ModuleConfig,
 ) -> WorkItemResult<B> {
+    assert!(module_config.emit_obj != EmitObj::None);
+
     let incr_comp_session_dir = cgcx.incr_comp_session_dir.as_ref().unwrap();
-    let mut object = None;
-    if let Some(saved_file) = module.source.saved_file {
-        let obj_out = cgcx.output_filenames.temp_path(OutputType::Object, Some(&module.name));
-        object = Some(obj_out.clone());
-        let source_file = in_incr_comp_dir(&incr_comp_session_dir, &saved_file);
-        debug!(
-            "copying pre-existing module `{}` from {:?} to {}",
-            module.name,
-            source_file,
-            obj_out.display()
-        );
-        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 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()
+    );
+    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
+        ));
     }
 
-    assert_eq!(object.is_some(), module_config.emit_obj != EmitObj::None);
-
     WorkItemResult::Compiled(CompiledModule {
         name: module.name,
         kind: ModuleKind::Regular,
-        object,
+        object: Some(obj_out),
         dwarf_object: None,
         bytecode: None,
     })

compiler/rustc_codegen_ssa/src/base.rs

@@ -716,7 +716,7 @@ pub fn codegen_crate<B: ExtraBackendMethods>(
                     &ongoing_codegen.coordinator_send,
                     CachedModuleCodegen {
                         name: cgu.name().to_string(),
-                        source: cgu.work_product(tcx),
+                        source: cgu.previous_work_product(tcx),
                     },
                 );
                 true
@@ -727,7 +727,7 @@ pub fn codegen_crate<B: ExtraBackendMethods>(
                     &ongoing_codegen.coordinator_send,
                     CachedModuleCodegen {
                         name: cgu.name().to_string(),
-                        source: cgu.work_product(tcx),
+                        source: cgu.previous_work_product(tcx),
                     },
                 );
                 true

compiler/rustc_incremental/src/persist/load.rs

@@ -162,18 +162,16 @@ pub fn load_dep_graph(sess: &Session) -> DepGraphFuture {
 
             for swp in work_products {
                 let mut all_files_exist = true;
-                if let Some(ref file_name) = swp.work_product.saved_file {
-                    let path = in_incr_comp_dir_sess(sess, file_name);
-                    if !path.exists() {
-                        all_files_exist = false;
-
-                        if sess.opts.debugging_opts.incremental_info {
-                            eprintln!(
-                                "incremental: could not find file for work \
+                let path = in_incr_comp_dir_sess(sess, &swp.work_product.saved_file);
+                if !path.exists() {
+                    all_files_exist = false;
+
+                    if sess.opts.debugging_opts.incremental_info {
+                        eprintln!(
+                            "incremental: could not find file for work \
                                     product: {}",
-                                path.display()
-                            );
-                        }
+                            path.display()
+                        );
                     }
                 }
 

compiler/rustc_incremental/src/persist/save.rs

@@ -107,20 +107,15 @@ 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!(
-                wp.saved_file.as_ref().map_or(true, |file_name| {
-                    !in_incr_comp_dir_sess(sess, &file_name).exists()
-                })
-            );
+            debug_assert!(!in_incr_comp_dir_sess(sess, &wp.saved_file).exists());
         }
     }
 
     // Check that we did not delete one of the current work-products:
     debug_assert!({
         new_work_products
             .iter()
-            .flat_map(|(_, wp)| wp.saved_file.iter())
-            .map(|name| in_incr_comp_dir_sess(sess, name))
+            .map(|(_, wp)| in_incr_comp_dir_sess(sess, &wp.saved_file))
             .all(|path| path.exists())
     });
 }

compiler/rustc_incremental/src/persist/work_product.rs

@@ -7,34 +7,30 @@ use rustc_fs_util::link_or_copy;
 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
 use rustc_session::Session;
 use std::fs as std_fs;
-use std::path::PathBuf;
+use std::path::Path;
 
 /// Copies a CGU work product to the incremental compilation directory, so next compilation can find and reuse it.
 pub fn copy_cgu_workproduct_to_incr_comp_cache_dir(
     sess: &Session,
     cgu_name: &str,
-    path: &Option<PathBuf>,
+    path: &Path,
 ) -> Option<(WorkProductId, WorkProduct)> {
     debug!("copy_cgu_workproduct_to_incr_comp_cache_dir({:?},{:?})", cgu_name, path);
     sess.opts.incremental.as_ref()?;
 
-    let saved_file = if let Some(path) = path {
-        let file_name = format!("{}.o", cgu_name);
-        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 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;
         }
-    } else {
-        None
     };
 
     let work_product = WorkProduct { cgu_name: cgu_name.to_string(), saved_file };
@@ -45,17 +41,15 @@ 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) {
-    if let Some(ref file_name) = work_product.saved_file {
-        let path = in_incr_comp_dir_sess(sess, file_name);
-        match std_fs::remove_file(&path) {
-            Ok(()) => {}
-            Err(err) => {
-                sess.warn(&format!(
-                    "file-system error deleting outdated file `{}`: {}",
-                    path.display(),
-                    err
-                ));
-            }
+    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
+            ));
         }
     }
 }

compiler/rustc_middle/src/mir/mono.rs

@@ -336,7 +336,7 @@ impl<'tcx> CodegenUnit<'tcx> {
         WorkProductId::from_cgu_name(self.name().as_str())
     }
 
-    pub fn work_product(&self, tcx: TyCtxt<'_>) -> WorkProduct {
+    pub fn previous_work_product(&self, tcx: TyCtxt<'_>) -> WorkProduct {
         let work_product_id = self.work_product_id();
         tcx.dep_graph
             .previous_work_product(&work_product_id)

compiler/rustc_query_system/src/dep_graph/dep_node.rs

@@ -164,7 +164,6 @@ pub struct WorkProductId {
 impl WorkProductId {
     pub fn from_cgu_name(cgu_name: &str) -> WorkProductId {
         let mut hasher = StableHasher::new();
-        cgu_name.len().hash(&mut hasher);
         cgu_name.hash(&mut hasher);
         WorkProductId { hash: hasher.finish() }
     }

compiler/rustc_query_system/src/dep_graph/graph.rs

@@ -887,7 +887,7 @@ impl<K: DepKind> DepGraph<K> {
 pub struct WorkProduct {
     pub cgu_name: String,
     /// Saved file associated with this CGU.
-    pub saved_file: Option<String>,
+    pub saved_file: String,
 }
 
 // Index type for `DepNodeData`'s edges.