feature(clean): accept source directories (#2288)

bin/clean.ml

@@ -6,7 +6,7 @@ let command =
     [ `S "DESCRIPTION"
     ; `P {|Removes files added by dune such as _build, <package>.install, and .merlin|}
     ; `P
-        {|If one or more PATH arguments are given, only remove those paths from the build directory.|}
+        {|If one or more PATH arguments are given, only those paths are removed from the build directory. A PATH may be a path inside the build directory (e.g. _build/default/foo) or a source directory (e.g. foo), in which case the corresponding artifacts are removed from every build context.|}
     ; `Blocks Common.help_secs
     ]
   in
@@ -18,30 +18,50 @@ let command =
        log file be useless but with some FS this also causes [dune clean] to fail (cf
        https://github.com/ocaml/dune/issues/2964). *)
     let builder = Common.Builder.disable_log_file builder in
-    let common, _config = Common.init builder in
+    let common, config = Common.init builder in
     Global_lock.lock_exn ();
     match paths with
     | [] ->
       Dune_engine.Target_promotion.files_in_source_tree_to_delete ()
       |> Path.Source.Set.iter ~f:(fun p -> Fpath.unlink_no_err (Path.Source.to_string p));
       Path.rm_rf Path.build_dir
     | paths ->
-      let build_path path =
-        let path = Path.of_string (Common.prefix_target common path) in
-        match Path.as_in_build_dir path with
-        | Some path -> path
-        | None ->
-          User_error.raise
-            [ Pp.textf
-                "%s is not inside the build directory"
-                (Path.to_string_maybe_quoted path)
-            ]
+      let remove_build_path path =
+        Dune_engine.Rule_cache.Workspace_local.remove_target path;
+        Dune_engine.Rule_cache.Workspace_local.remove_subtree path;
+        Path.rm_rf (Path.build path)
       in
-      List.iter paths ~f:(fun path ->
-        let path = build_path path in
-        let () = Dune_engine.Rule_cache.Workspace_local.remove_target path in
-        let () = Dune_engine.Rule_cache.Workspace_local.remove_subtree path in
-        Path.rm_rf (Path.build path))
+      (* Paths already inside the build directory are removed as is. Source paths
+         (including the project root) are resolved against every build context,
+         mirroring how [dune build] accepts source directories. *)
+      let build_paths, source_paths =
+        List.partition_map paths ~f:(fun path ->
+          let path = Path.of_string (Common.prefix_target common path) in
+          match Path.as_in_build_dir path with
+          | Some path -> Left path
+          | None ->
+            (match Path.as_in_source_tree path with
+             | Some src -> Right src
+             | None ->
+               User_error.raise
+                 [ Pp.textf
+                     "%s is not inside the build directory or the source tree"
+                     (Path.to_string_maybe_quoted path)
+                 ]))
+      in
+      let source_build_paths =
+        match source_paths with
+        | [] -> []
+        | _ :: _ ->
+          Scheduler_setup.go_without_rpc_server ~common ~config (fun () ->
+            Memo.run
+              (let open Memo.O in
+               let+ contexts = Context.DB.all () in
+               List.concat_map source_paths ~f:(fun src ->
+                 List.map contexts ~f:(fun ctx ->
+                   Path.Build.append_source (Context.build_dir ctx) src))))
+      in
+      List.iter (build_paths @ source_build_paths) ~f:remove_build_path
   in
   Cmd.v (Cmd.info "clean" ~doc ~man) term
 ;;

doc/changes/added/15305.md

@@ -0,0 +1,5 @@
+- `dune clean` now accepts source directories (and the project root) in
+  addition to paths inside the build directory. For example, `dune clean foo`
+  removes the build artifacts under the source directory `foo` from every build
+  context, mirroring how `dune build foo` accepts a source directory.
+  (#15305, fixes #2288, @rgrinberg)

test/blackbox-tests/test-cases/clean.t

@@ -36,9 +36,9 @@ We can clean the entire workspace to re-run everything:
   foo
   bar
 
-Issue #2288: unlike `dune build`, `dune clean` does not accept source
-directories (or package names); it only accepts paths inside the build
-directory. So cleaning a source directory, or the project root, is rejected.
+Issue #2288: `dune clean` also accepts source directories, not just paths
+inside the build directory, mirroring `dune build`. The corresponding artifacts
+are removed from every build context.
 
   $ mkdir sub
   $ cat >sub/dune <<EOF
@@ -47,19 +47,21 @@ directory. So cleaning a source directory, or the project root, is rejected.
   >  (action (bash "touch baz && echo baz")))
   > EOF
 
-`dune build` accepts the source directory:
-
   $ dune build sub
   baz
+  $ test -e _build/default/sub/baz && echo built
+  built
 
-But `dune clean` rejects it:
+Cleaning the source directory removes its artifacts, leaving the rest intact:
 
   $ dune clean sub
-  Error: sub is not inside the build directory
-  [1]
+  $ test -e _build/default/sub && echo present || echo removed
+  removed
+  $ test -e _build/default/foo && echo present || echo removed
+  present
 
-The project root is rejected too:
+Cleaning the project root cleans the whole build context:
 
   $ dune clean .
-  Error: . is not inside the build directory
-  [1]
+  $ test -e _build/default && echo present || echo removed
+  removed