Allow to set the library path at configure time (#575)

This allow to drop the dependency on ocamlfind

.gitignore

@@ -10,3 +10,4 @@ bootstrap.cmi
 bootstrap.cmo
 bootstrap.exe
 Makefile.dev
+src/setup.ml

CHANGES.md

@@ -7,6 +7,9 @@ next
   compiler is not installed but still has a META file (#574, fixes
   #563)
 
+- Do not depend on ocamlfind. Instead, hard-code the library path when
+  installing from opam (#575)
+
 - Reduce interleaving in the scheduler in an attempt to make Jbuilder
   keep file descriptors open for less long (#586)
 

Makefile

@@ -41,6 +41,9 @@ clean:
 	$(BIN) clean
 	rm -f ./boot.exe $(wildcard ./bootstrap.cmi ./bootstrap.cmo ./bootstrap.exe)
 
+distclean: clean
+	rm -f src/setup.ml
+
 doc:
 	cd doc && sphinx-build . _build
 

configure

@@ -0,0 +1,2 @@
+#!/bin/sh
+exec ocaml configure.ml "$@"

configure.ml

@@ -0,0 +1,40 @@
+#!/usr/bin/env ocaml
+
+open StdLabels
+open Printf
+
+let list f l = sprintf "[%s]" (String.concat ~sep:"; " (List.map l ~f))
+let string s = sprintf "%S" s
+let option f = function
+  | None -> "None"
+  | Some x -> sprintf "Some %s" (f x)
+
+let () =
+  let bad fmt = ksprintf (fun s -> raise (Arg.Bad s)) fmt in
+  let library_path = ref None in
+  let library_destdir = ref None in
+  let set_libdir s =
+    let dir =
+      if Filename.is_relative s then
+        Filename.concat (Sys.getcwd ()) s
+      else
+        s
+    in
+    library_path    := Some [dir];
+    library_destdir := Some dir
+  in
+  let args =
+    [ "--libdir", Arg.String set_libdir,
+      "DIR where installed libraries are for the default build context"
+    ]
+  in
+  let anon s =
+    bad "Don't know what to do with %s" s
+  in
+  Arg.parse (Arg.align args)
+    anon "Usage: ocaml configure.ml [OPTRIONS]]\nOptions are:";
+  let oc = open_out "src/setup.ml" in
+  let pr fmt = fprintf oc (fmt ^^ "\n") in
+  pr "let library_path    = %s" (option (list string) !library_path);
+  pr "let library_destdir = %s" (option string        !library_destdir);
+  close_out oc

jbuilder.opam

@@ -6,17 +6,9 @@ bug-reports: "https://github.com/ocaml/dune/issues"
 dev-repo: "https://github.com/ocaml/dune.git"
 license: "Apache-2.0"
 build: [
+  ["ocaml" "configure.ml" "--libdir" lib]
   ["ocaml" "bootstrap.ml"]
   ["./boot.exe" "--subst"] {pinned}
   ["./boot.exe" "-j" jobs]
 ]
-depends: [
-  # ocamlfind is not mandatory to build packages using
-  # jbuilder. However if it is present jbuilder will use it.  Making
-  # it a hard-dependency avoids problems when there is a previous
-  # ocamlfind in the PATH. We make it a "build" depepdency even though
-  # it is only a runtime dependency so that reinstalling ocamlfind
-  # doesn't resintall jbuilder
-  "ocamlfind" {build}
-]
 available: [ ocaml-version >= "4.02.3" ]

src/context.ml

@@ -136,7 +136,8 @@ let opam_config_var ~env ~cache var =
     match Bin.opam with
     | None -> Fiber.return None
     | Some fn ->
-      Process.run_capture (Accept All) (Path.to_string fn) ~env ["config"; "var"; var]
+      Process.run_capture (Accept All) (Path.to_string fn) ~env
+        ["config"; "var"; var]
       >>| function
       | Ok s ->
         let s = String.trim s in
@@ -180,7 +181,7 @@ let extend_env ~vars ~env =
     |> Array.of_list
 
 let create ~(kind : Kind.t) ~path ~base_env ~env_extra ~name ~merlin
-      ~use_findlib ~targets () =
+      ~targets () =
   let env = extend_env ~env:base_env ~vars:env_extra in
   let opam_var_cache = Hashtbl.create 128 in
   (match kind with
@@ -251,7 +252,10 @@ let create ~(kind : Kind.t) ~path ~base_env ~env_extra ~name ~merlin
 
     let build_dir = Path.of_string (sprintf "_build/%s" name) in
     let findlib_path () =
-      if use_findlib then
+      match kind, findlib_toolchain, Setup.library_path with
+      | Default, None, Some l ->
+        Fiber.return (List.map l ~f:Path.absolute)
+      | _ ->
         (* If ocamlfind is present, it has precedence over everything else. *)
         match which "ocamlfind" with
         | Some fn ->
@@ -270,11 +274,9 @@ let create ~(kind : Kind.t) ~path ~base_env ~env_extra ~name ~merlin
           >>| function
           | Some s -> [Path.absolute s]
           | None ->
-            (* If neither opam neither ocamlfind are present, assume that libraries are
-               [dir ^ "/../lib"] *)
+            (* If neither opam neither ocamlfind are present, assume
+               that libraries are [dir ^ "/../lib"] *)
             [Path.relative (Path.parent dir) "lib"]
-      else
-        Fiber.return []
     in
     Fiber.fork_and_join
       findlib_path
@@ -282,9 +284,10 @@ let create ~(kind : Kind.t) ~path ~base_env ~env_extra ~name ~merlin
     >>= fun (findlib_path, ocamlc_config) ->
     let version = Ocamlc_config.version ocamlc_config in
     let env, env_extra =
-      (* See comment in ansi_color.ml for setup_env_for_colors. For OCaml < 4.05,
-         OCAML_COLOR is not supported so we use OCAMLPARAM. OCaml 4.02 doesn't support
-         'color' in OCAMLPARAM, so we just don't force colors with 4.02. *)
+      (* See comment in ansi_color.ml for setup_env_for_colors. For
+         OCaml < 4.05, OCAML_COLOR is not supported so we use
+         OCAMLPARAM. OCaml 4.02 doesn't support 'color' in OCAMLPARAM,
+         so we just don't force colors with 4.02. *)
       if !Clflags.capture_outputs
       && Lazy.force Colors.stderr_supports_colors
       && version >= (4, 03, 0)
@@ -397,7 +400,7 @@ let initial_env = lazy (
   Lazy.force Colors.setup_env_for_colors;
   Unix.environment ())
 
-let default ?(merlin=true) ?(use_findlib=true) ~targets () =
+let default ?(merlin=true) ~targets () =
   let env = Lazy.force initial_env in
   let path =
     match get_env env "PATH" with
@@ -405,7 +408,7 @@ let default ?(merlin=true) ?(use_findlib=true) ~targets () =
     | None -> []
   in
   create ~kind:Default ~path ~base_env:env ~env_extra:Env_var_map.empty
-    ~name:"default" ~merlin ~use_findlib ~targets ()
+    ~name:"default" ~merlin ~targets ()
 
 let create_for_opam ?root ~targets ~switch ~name ?(merlin=false) () =
   match Bin.opam with
@@ -445,11 +448,11 @@ let create_for_opam ?root ~targets ~switch ~name ?(merlin=false) () =
     in
     let env = Lazy.force initial_env in
     create ~kind:(Opam { root; switch }) ~targets
-      ~path ~base_env:env ~env_extra:vars ~name ~merlin ~use_findlib:true ()
+      ~path ~base_env:env ~env_extra:vars ~name ~merlin ()
 
-let create ?use_findlib ?merlin def =
+let create ?merlin def =
   match (def : Workspace.Context.t) with
-  | Default targets -> default ~targets ?merlin ?use_findlib ()
+  | Default targets -> default ~targets ?merlin ()
   | Opam { name; switch; root; targets; _ } ->
     create_for_opam ?root ~switch ~name ?merlin ~targets ()
 
@@ -461,15 +464,19 @@ let install_prefix t =
   | None   -> Path.parent t.ocaml_bin
 
 let install_ocaml_libdir t =
-  (* If ocamlfind is present, it has precedence over everything else. *)
-  match which t "ocamlfind" with
-  | Some fn ->
-    (Process.run_capture_line ~env:t.env Strict
-       (Path.to_string fn) ["printconf"; "destdir"]
-     >>| fun s ->
-     Some (Path.absolute s))
-  | None ->
-    Fiber.return None
+  match t.kind, t.findlib_toolchain, Setup.library_destdir with
+  | Default, None, Some d ->
+    Fiber.return (Some (Path.absolute d))
+  | _ ->
+    (* If ocamlfind is present, it has precedence over everything else. *)
+    match which t "ocamlfind" with
+    | Some fn ->
+      (Process.run_capture_line ~env:t.env Strict
+         (Path.to_string fn) ["printconf"; "destdir"]
+       >>| fun s ->
+       Some (Path.absolute s))
+    | None ->
+      Fiber.return None
 
 (* CR-someday jdimino: maybe we should just do this for [t.env] directly? *)
 let env_for_exec t =

src/context.mli

@@ -129,12 +129,8 @@ val sexp_of_t : t -> Sexp.t
 (** Compare the context names *)
 val compare : t -> t -> Ordering.t
 
-(** If [use_findlib] is [false], don't try to guess the library search path with opam or
-    ocamlfind. This is only for building jbuilder itself, so that its build is completely
-    independent of the user setup. *)
 val create
-  :  ?use_findlib:bool
-  -> ?merlin:bool
+  :  ?merlin:bool
   -> Workspace.Context.t
   -> t list Fiber.t
 

src/jbuild

@@ -13,3 +13,8 @@
   (synopsis    "Internal Jbuilder library, do not use!")))
 
 (ocamllex (meta_lexer glob_lexer))
+
+(rule
+ ((targets (setup.ml))
+  (mode    fallback)
+  (action  (copy# setup.defaults.ml setup.ml))))

src/main.ml

@@ -21,7 +21,6 @@ let package_install_file { packages; _ } pkg =
 let setup ?(log=Log.no_log)
       ?filter_out_optional_stanzas_with_missing_deps
       ?workspace ?(workspace_file="jbuild-workspace")
-      ?(use_findlib=true)
       ?only_packages
       ?extra_ignored_subtrees
       ?x
@@ -56,11 +55,12 @@ let setup ?(log=Log.no_log)
 
   Fiber.parallel_map workspace.contexts ~f:(fun ctx_def ->
     let name = Workspace.Context.name ctx_def in
-    Context.create ctx_def ~merlin:(workspace.merlin_context = Some name) ~use_findlib)
+    Context.create ctx_def ~merlin:(workspace.merlin_context = Some name))
   >>= fun contexts ->
   let contexts = List.concat contexts in
   List.iter contexts ~f:(fun (ctx : Context.t) ->
-    Log.infof log "@[<1>Jbuilder context:@,%a@]@." Sexp.pp (Context.sexp_of_t ctx));
+    Log.infof log "@[<1>Jbuilder context:@,%a@]@." Sexp.pp
+      (Context.sexp_of_t ctx));
   let rule_done  = ref 0 in
   let rule_total = ref 0 in
   let gen_status_line () =
@@ -168,7 +168,6 @@ let bootstrap () =
     Scheduler.go ~log ~config
       (setup ~log ~workspace:{ merlin_context = Some "default"
                              ; contexts = [Default [Native]] }
-         ~use_findlib:false
          ~extra_ignored_subtrees:ignored_during_bootstrap
          ()
        >>= fun { build_system = bs; _ } ->
@@ -183,7 +182,7 @@ let bootstrap () =
     Report_error.report exn;
     exit 1
 
-let setup = setup ~use_findlib:true ~extra_ignored_subtrees:Path.Set.empty
+let setup = setup ~extra_ignored_subtrees:Path.Set.empty
 
 let find_context_exn t ~name =
   match List.find t.contexts ~f:(fun c -> c.name = name) with

src/setup.boot.ml

@@ -0,0 +1,2 @@
+let library_path    = Some []
+let library_destdir = None

src/setup.defaults.ml

@@ -0,0 +1,2 @@
+let library_path    = None
+let library_destdir = None

src/setup.mli

@@ -0,0 +1,12 @@
+(** Setup of Jbuilder *)
+
+(** These parameters are set by [ocaml configure.ml] or copied from
+    [setup.defaults.ml]. During bootstrap, values from [setup.boot.ml]
+    are used *)
+
+(** Where to find installed libraries for the default context. If
+    [None], auto-detect it using standard tools such as [ocamlfind]. *)
+val library_path : string list option
+
+(** Where to install libraries for the default context. *)
+val library_destdir : string option