Remove the external-lib-deps command

CHANGES.md

@@ -74,6 +74,10 @@ Unreleased
 - Automatically delete left-over Merlin files when rebuilding for the first time
   a project previously built with Dune `<= 2.7`. (#4261, @voodoos, @aalekseyev)
 
+- Remove the `external-lib-deps` command. This command was only
+  approximative and the cost of maintainance was getting too high. We
+  removed it to make room for new more important features
+
 2.8.2 (21/01/2021)
 ------------------
 

bin/build_cmd.ml

@@ -72,11 +72,7 @@ let runtest =
   let term =
     let+ common = Common.term
     and+ dirs = Arg.(value & pos_all string [ "." ] name_) in
-    Common.set_common common
-      ~targets:
-        (List.map dirs ~f:(fun s ->
-             let dir = Path.Local.of_string s in
-             Arg.Dep.alias_rec ~dir Dune_engine.Alias.Name.runtest));
+    Common.set_common common;
     let targets (setup : Import.Main.build_system) =
       List.map dirs ~f:(fun dir ->
           let dir = Path.(relative root) (Common.prefix_target common dir) in
@@ -116,7 +112,7 @@ let build =
       | [] -> [ Common.default_target common ]
       | _ :: _ -> targets
     in
-    Common.set_common common ~targets;
+    Common.set_common common;
     let targets setup = Target.resolve_targets_exn common setup targets in
     run_build_command ~common ~targets
   in

bin/clean.ml

@@ -17,7 +17,7 @@ let command =
        includes deleting the log file. Not only creating the log file would be
        useless but with some FS this also causes [dune clean] to fail (cf
        https://github.com/ocaml/dune/issues/2964). *)
-    Common.set_common common ~targets:[] ~log_file:No_log_file;
+    Common.set_common common ~log_file:No_log_file;
     Build_system.files_in_source_tree_to_delete ()
     |> Path.Set.iter ~f:Path.unlink_no_err;
     Path.rm_rf Path.build_dir

bin/common.ml

@@ -114,12 +114,10 @@ let normalize_path path =
   else
     path
 
-let set_dirs c =
+let set_common ?log_file c =
   if c.root.dir <> Filename.current_dir_name then Sys.chdir c.root.dir;
   Path.set_root (normalize_path (Path.External.cwd ()));
-  Path.Build.set_build_dir (Path.Build.Kind.of_string c.build_dir)
-
-let set_common_other ?log_file c ~targets =
+  Path.Build.set_build_dir (Path.Build.Kind.of_string c.build_dir);
   Dune_config.init c.config;
   Dune_util.Log.init () ?file:log_file;
   Clflags.debug_dep_path := c.debug_dep_path;
@@ -134,22 +132,10 @@ let set_common_other ?log_file c ~targets =
   Clflags.no_print_directory := c.no_print_directory;
   Clflags.store_orig_src_dir := c.store_orig_src_dir;
   Clflags.promote_install_files := c.promote_install_files;
-  Clflags.external_lib_deps_hint :=
-    List.concat
-      [ [ "dune"; "external-lib-deps"; "--missing" ]
-      ; c.orig_args
-      ; List.map ~f:Arg.Dep.to_string_maybe_quoted targets
-      ];
   Clflags.always_show_command_line := c.always_show_command_line;
   Clflags.ignore_promoted_rules := c.ignore_promoted_rules;
   Option.iter ~f:Dune_engine.Stats.enable c.stats_trace_file
 
-let set_common ?log_file ?external_lib_deps_mode c ~targets =
-  Option.iter external_lib_deps_mode ~f:(fun x ->
-      Clflags.external_lib_deps_mode := x);
-  set_dirs c;
-  set_common_other ?log_file c ~targets
-
 let footer =
   `Blocks
     [ `S "BUGS"

bin/common.mli

@@ -34,27 +34,10 @@ val prefix_target : t -> string -> string
 
 val instrument_with : t -> Dune_engine.Lib_name.t list option
 
-(** [set_common ?log common ~targets ~external_lib_deps_mode] is
-    [set_dirs common] followed by [set_common_other common ~targets]. In
-    general, [set_common] executes sequence of side-effecting actions to
-    initialize Dune's working environment based on the options determined in a
-    [Common.t] record.contents. *)
-val set_common :
-     ?log_file:Dune_util.Log.File.t
-  -> ?external_lib_deps_mode:bool
-  -> t
-  -> targets:Arg.Dep.t list
-  -> unit
-
-(** [set_common_other common ~targets] sets all stateful values dictated by
-    [common], except those accounted for by [set_dirs]. [targets] are used to
-    obtain external library dependency hints, if needed. *)
-val set_common_other :
-  ?log_file:Dune_util.Log.File.t -> t -> targets:Arg.Dep.t list -> unit
-
-(** [set_dirs common] sets the workspace root and build directories, and makes
-    the root the current working directory *)
-val set_dirs : t -> unit
+(** [set_common] executes sequence of side-effecting actions to initialize
+    Dune's working environment based on the options determined in a [Common.t]
+    record.contents. *)
+val set_common : ?log_file:Dune_util.Log.File.t -> t -> unit
 
 (** [examples \[("description", "dune cmd foo"); ...\]] is an [EXAMPLES] manpage
     section of enumerated examples illustrating how to run the documented

bin/compute.ml

@@ -29,7 +29,7 @@ let term =
          & info [] ~docv:"INPUT"
              ~doc:"Use $(docv) as the input to the function.")
      in
-     Common.set_common common ~targets:[] ~external_lib_deps_mode:true;
+     Common.set_common common;
      let action =
        Scheduler.go ~common (fun () ->
            let open Fiber.O in

bin/describe.ml

@@ -302,7 +302,7 @@ let term =
   and+ context_name = Common.context_arg ~doc:"Build context to use."
   and+ format = Format.arg
   and+ lang = Lang.arg in
-  Common.set_common common ~targets:[] ~external_lib_deps_mode:false;
+  Common.set_common common;
   let what = What.parse what ~lang in
   Scheduler.go ~common (fun () ->
       let open Fiber.O in

bin/exec.ml

@@ -43,7 +43,7 @@ let term =
       value & flag
       & info [ "no-build" ] ~doc:"don't rebuild target before executing")
   and+ args = Arg.(value & pos_right 0 string [] (Arg.info [] ~docv:"ARGS")) in
-  Common.set_common common ~targets:[ Arg.Dep.file prog ];
+  Common.set_common common;
   let setup =
     Scheduler.go ~common (fun () -> Memo.Build.run (Import.Main.setup common))
   in

bin/external_lib_deps.ml

@@ -1,188 +1,28 @@
-open Stdune
+open! Stdune
 open Import
 
-let pp_external_libs libs =
-  Pp.enumerate (Lib_name.Map.to_list libs) ~f:(fun (name, kind) ->
-      match (kind : Lib_deps_info.Kind.t) with
-      | Optional -> Pp.textf "%s (optional)" (Lib_name.to_string name)
-      | Required -> Pp.textf "%s" (Lib_name.to_string name))
-
-let doc = "Print out external libraries needed to build the given targets."
+let doc = "Removed command."
 
 let man =
   [ `S "DESCRIPTION"
-  ; `P {|Print out the external libraries needed to build the given targets.|}
   ; `P
-      {|The output of $(b,dune external-lib-deps @install) should be included
-          in what is written in your $(i,<package>.opam) file.|}
+      "This subcommand used to print out anapproximate set of external \
+       libraries that were required for building a given set of targets, \
+       without running the build. While this feature was useful, over time the \
+       quality of approximation had degraded and the cost of maintenance had \
+       increased, so we decided to remove it.\n"
   ; `Blocks Common.help_secs
   ]
 
 let info = Term.info "external-lib-deps" ~doc ~man
 
-let all_lib_deps ~request =
-  let targets = Build_system.static_deps_of_request request in
-  let rules = Build_system.rules_for_transitive_closure targets in
-  let lib_deps =
-    List.map rules ~f:(fun (rule : Dune_engine.Rule.t) ->
-        let deps = Lib_deps_info.lib_deps rule.action.build in
-        (rule, deps))
-  in
-  let module Context_name = Dune_engine.Context_name in
-  let contexts = Build_system.contexts () in
-  List.fold_left lib_deps ~init:[]
-    ~f:(fun acc ((rule : Dune_engine.Rule.t), deps) ->
-      if Lib_name.Map.is_empty deps then
-        acc
-      else
-        match Path.Build.extract_build_context rule.dir with
-        | None -> acc
-        | Some (context, p) ->
-          let context = Context_name.of_string context in
-          (context, (p, deps)) :: acc)
-  |> Context_name.Map.of_list_multi
-  |> Context_name.Map.filteri ~f:(fun ctx _ ->
-         Context_name.Map.mem contexts ctx)
-  |> Context_name.Map.map
-       ~f:(Path.Source.Map.of_list_reduce ~f:Lib_deps_info.merge)
-
-let opam_install_command ?switch_name packages =
-  let cmd =
-    match switch_name with
-    | Some name -> Printf.sprintf "opam install --switch=%s" name
-    | None -> "opam install"
-  in
-  cmd :: packages |> String.concat ~sep:" "
-
-let run ~lib_deps ~by_dir ~setup ~only_missing ~sexp =
-  Dune_engine.Context_name.Map.foldi lib_deps ~init:false
-    ~f:(fun context_name lib_deps_by_dir acc ->
-      let lib_deps =
-        Path.Source.Map.values lib_deps_by_dir
-        |> List.fold_left ~init:Lib_name.Map.empty ~f:Lib_deps_info.merge
-      in
-      let sctx =
-        Dune_engine.Context_name.Map.find_exn setup.Import.Main.scontexts
-          context_name
-      in
-      let switch_name =
-        match (Super_context.context sctx).Context.kind with
-        | Default -> None
-        | Opam { switch; _ } -> Some switch
-      in
-      let internals = Super_context.internal_lib_names sctx in
-      let is_external name _kind = not (Lib_name.Set.mem internals name) in
-      let externals = Lib_name.Map.filteri lib_deps ~f:is_external in
-      if only_missing then (
-        if by_dir || sexp then
-          User_error.raise
-            [ Pp.textf
-                "--only-missing cannot be used with --unstable-by-dir or --sexp"
-            ];
-        let context =
-          List.find_exn setup.workspace.contexts ~f:(fun c ->
-              Dune_engine.Context_name.equal c.name context_name)
-        in
-        let missing =
-          Lib_name.Map.filteri externals ~f:(fun name _ ->
-              not (Findlib.available context.findlib name))
-        in
-        if Lib_name.Map.is_empty missing then
-          acc
-        else if
-          Lib_name.Map.for_alli missing ~f:(fun _ kind ->
-              kind = Lib_deps_info.Kind.Optional)
-        then (
-          User_message.prerr
-            (User_error.make
-               [ Pp.textf
-                   "The following libraries are missing in the %s context:"
-                   (Dune_engine.Context_name.to_string context_name)
-               ; pp_external_libs missing
-               ]);
-          false
-        ) else
-          let required_package_names =
-            Lib_name.Map.to_list missing
-            |> List.filter_map ~f:(fun (name, kind) ->
-                   match (kind : Lib_deps_info.Kind.t) with
-                   | Optional -> None
-                   | Required -> Some (Lib_name.package_name name))
-            |> Package.Name.Set.of_list |> Package.Name.Set.to_list
-            |> List.map ~f:Package.Name.to_string
-          in
-          User_message.prerr
-            (User_error.make
-               [ Pp.textf
-                   "The following libraries are missing in the %s context:"
-                   (Dune_engine.Context_name.to_string context_name)
-               ; pp_external_libs missing
-               ]
-               ~hints:
-                 [ Dune_engine.Utils.pp_command_hint
-                     (opam_install_command ?switch_name required_package_names)
-                 ]);
-          true
-      ) else if sexp then (
-        if not by_dir then
-          User_error.raise [ Pp.textf "--sexp requires --unstable-by-dir" ];
-        let lib_deps_by_dir =
-          lib_deps_by_dir
-          |> Path.Source.Map.map ~f:(Lib_name.Map.filteri ~f:is_external)
-          |> Path.Source.Map.filter ~f:(fun m -> not (Lib_name.Map.is_empty m))
-        in
-        let sexp =
-          Path.Source.Map.to_dyn Lib_deps_info.to_dyn lib_deps_by_dir
-          |> Sexp.of_dyn
-        in
-        Format.printf "%a@." Pp.to_fmt
-          (Sexp.pp
-             (List
-                [ Atom (Dune_engine.Context_name.to_string context_name); sexp ]));
-        acc
-      ) else (
-        if by_dir then
-          User_error.raise
-            [ Pp.textf "--unstable-by-dir cannot be used without --sexp" ];
-        User_message.print
-          (User_message.make
-             [ Pp.textf
-                 "These are the external library dependencies in the %s \
-                  context:"
-                 (Dune_engine.Context_name.to_string context_name)
-             ; pp_external_libs externals
-             ]);
-        acc
-      ))
-
 let term =
-  let+ common = Common.term
-  and+ only_missing =
-    Arg.(
-      value & flag
-      & info [ "missing" ] ~doc:{|Only print out missing dependencies|})
-  and+ targets = Arg.(non_empty & pos_all dep [] & Arg.info [] ~docv:"TARGET")
-  and+ by_dir =
-    Arg.(
-      value & flag
-      & info [ "unstable-by-dir" ]
-          ~doc:
-            {|Print dependencies per directory
-                    (this feature is currently unstable)|})
-  and+ sexp =
-    Arg.(value & flag & info [ "sexp" ] ~doc:{|Produce a s-expression output|})
-  in
-  Common.set_common common ~targets:[] ~external_lib_deps_mode:true;
-  let setup, lib_deps =
-    Scheduler.go ~common (fun () ->
-        let open Fiber.O in
-        let+ setup = Memo.Build.run (Import.Main.setup common) in
-        let targets = Target.resolve_targets_exn common setup targets in
-        let request = Target.request targets in
-        let deps = all_lib_deps ~request in
-        (setup, deps))
-  in
-  let failure = run ~by_dir ~setup ~lib_deps ~sexp ~only_missing in
-  if failure then raise Dune_util.Report_error.Already_reported
+  Term.ret
+  @@ let+ _ = Common.term
+     and+ _ = Arg.(value & flag & info [ "missing" ] ~doc:{|unused|})
+     and+ _ = Arg.(value & pos_all dep [] & Arg.info [] ~docv:"TARGET")
+     and+ _ = Arg.(value & flag & info [ "unstable-by-dir" ] ~doc:{|unused|})
+     and+ _ = Arg.(value & flag & info [ "sexp" ] ~doc:{|unused|}) in
+     `Error (false, "This subcommand is no longer implemented.")
 
 let command = (term, info)

bin/import.ml

@@ -6,7 +6,6 @@ module Super_context = Dune_rules.Super_context
 module Context = Dune_rules.Context
 module Config = Dune_engine.Config
 module Lib_name = Dune_engine.Lib_name
-module Lib_deps_info = Dune_rules.Lib_deps_info
 module Build_system = Dune_engine.Build_system
 module Findlib = Dune_rules.Findlib
 module Package = Dune_engine.Package

bin/init.ml

@@ -209,7 +209,7 @@ let term =
       & opt (some (enum Component.Options.Project.Pkg.commands)) None
       & info [ "pkg" ] ~docv ~doc)
   in
-  Common.set_common common_term ~targets:[];
+  Common.set_common common_term;
   let open Component in
   let context = Init_context.make path in
   let common : Options.Common.t = { name; libraries; pps } in

bin/install_uninstall.ml

@@ -377,7 +377,7 @@ let install_uninstall ~what =
               "Select context to install from. By default, install files from \
                all defined contexts.")
     and+ sections = Sections.term in
-    Common.set_common ~log_file:No_log_file common ~targets:[];
+    Common.set_common ~log_file:No_log_file common;
     Scheduler.go ~common (fun () ->
         let open Fiber.O in
         let* workspace = Memo.Build.run (Import.Main.scan_workspace common) in

bin/installed_libraries.ml

@@ -13,7 +13,7 @@ let term =
       & info [ "na"; "not-available" ]
           ~doc:"List libraries that are not available and explain why")
   in
-  Common.set_common common ~targets:[];
+  Common.set_common common;
   let capture_outputs = Common.capture_outputs common in
   let _env : Env.t = Import.Main.setup_env ~capture_outputs in
   Scheduler.go ~common (fun () ->

bin/ocaml_merlin.ml

@@ -28,7 +28,7 @@ let term =
              debugging purposes only and should not be considered as a stable \
              ouptut.")
   in
-  Common.set_common common ~log_file:No_log_file ~targets:[];
+  Common.set_common common ~log_file:No_log_file;
   Dune_engine.File_tree.init ~recognize_jbuilder_projects:true
     ~ancestor_vcs:None;
   let x = Common.x common in
@@ -69,7 +69,7 @@ module Dump_dot_merlin = struct
               "The path to the folder of which the configuration should be \
                printed. Defaults to the current directory.")
     in
-    Common.set_common common ~log_file:No_log_file ~targets:[];
+    Common.set_common common ~log_file:No_log_file;
     Dune_engine.File_tree.init ~recognize_jbuilder_projects:true
       ~ancestor_vcs:None;
     let x = Common.x common in