Assert incr comp in copy_cgu_workproduct_to_incr_comp_cache_dir

It was already only called when incr comp is enabled and this allows
cleaning up the callers a bit.

Author: bjorn3

compiler/rustc_codegen_ssa/src/back/write.rs

@@ -489,14 +489,13 @@ fn copy_all_cgu_workproducts_to_incr_comp_cache_dir(
         if let Some(path) = &module.bytecode {
             files.push((OutputType::Bitcode.extension(), path.as_path()));
         }
-        if let Some((id, product)) = copy_cgu_workproduct_to_incr_comp_cache_dir(
+        let (id, product) = copy_cgu_workproduct_to_incr_comp_cache_dir(
             sess,
             &module.name,
             files.as_slice(),
             &module.links_from_incr_cache,
-        ) {
-            work_products.insert(id, product);
-        }
+        );
+        work_products.insert(id, product);
     }
 
     work_products

compiler/rustc_incremental/src/persist/work_product.rs

@@ -16,14 +16,16 @@ use crate::persist::fs::*;
 
 /// Copies a CGU work product to the incremental compilation directory, so next compilation can
 /// find and reuse it.
+///
+/// Panics when incr comp is disabled.
 pub fn copy_cgu_workproduct_to_incr_comp_cache_dir(
     sess: &Session,
     cgu_name: &str,
     files: &[(&'static str, &Path)],
     known_links: &[PathBuf],
-) -> Option<(WorkProductId, WorkProduct)> {
+) -> (WorkProductId, WorkProduct) {
     debug!(?cgu_name, ?files);
-    sess.opts.incremental.as_ref()?;
+    assert!(sess.opts.incremental.is_some());
 
     let mut saved_files = UnordMap::default();
     for (ext, path) in files {
@@ -50,7 +52,7 @@ pub fn copy_cgu_workproduct_to_incr_comp_cache_dir(
     let work_product = WorkProduct { cgu_name: cgu_name.to_string(), saved_files };
     debug!(?work_product);
     let work_product_id = WorkProductId::from_cgu_name(cgu_name);
-    Some((work_product_id, work_product))
+    (work_product_id, work_product)
 }
 
 /// Removes files for a given work product.

compiler/rustc_interface/src/queries.rs

@@ -89,14 +89,13 @@ impl Linker {
 
         if sess.opts.incremental.is_some()
             && let Some(path) = self.metadata.path()
-            && let Some((id, product)) =
-                rustc_incremental::copy_cgu_workproduct_to_incr_comp_cache_dir(
-                    sess,
-                    "metadata",
-                    &[("rmeta", path)],
-                    &[],
-                )
         {
+            let (id, product) = rustc_incremental::copy_cgu_workproduct_to_incr_comp_cache_dir(
+                sess,
+                "metadata",
+                &[("rmeta", path)],
+                &[],
+            );
             work_products.insert(id, product);
         }