Rollup merge of #97058 - bjorn3:multi_artifact_work_products, r=nagisa

Various refactors to the incr comp workproduct handling

This is the result of me looking into adding support for having multiple object files for a single codegen unit to incr comp. This is necessary to support inline assembly in cg_clif without requiring partial linking which is not supported on Windows and seems to fail on macOS for some reason. Cg_clif uses an external assembler to handle inline asm and thus produces one object file with regular functions and one object file containing compiled inline asm for each codegen unit which uses inline asm. Current incr comp can't handle this. This PR doesn't yet add support for this, but it makes it easier to do so.

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;
+                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 \
+                    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

@@ -107,11 +107,7 @@ 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());
         }
     }
 
@@ -119,8 +115,7 @@ pub fn save_work_product_index(
     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
+            ));
         }
     }
 }