feat: support libraries with the same name in multiple contexts

Signed-off-by: Javier Chávarri <javier.chavarri@gmail.com>
Signed-off-by: Antonio Nuno Monteiro <anmonteiro@gmail.com>

bin/describe/describe_workspace.ml

@@ -449,9 +449,10 @@ module Crawl = struct
         | true ->
           (* XXX why do we have a second object directory? *)
           let* modules_, obj_dir_ =
+            let sentinel = Lib.sentinel lib in
             Dir_contents.get sctx ~dir:(Path.as_in_build_dir_exn src_dir)
             >>= Dir_contents.ocaml
-            >>| Ml_sources.modules_and_obj_dir ~for_:(Library name)
+            >>| Ml_sources.modules_and_obj_dir ~for_:(Library sentinel)
           in
           let* pp_map =
             let+ version =

src/dune_rules/dir_contents.ml

@@ -451,13 +451,19 @@ end
 include Load
 
 let modules_of_local_lib sctx lib =
-  let info = Lib.Local.info lib in
-  let* t =
-    let dir = Lib_info.src_dir info in
-    get sctx ~dir
+  let+ sources =
+    let* t =
+      let info = Lib.Local.info lib in
+      let dir = Lib_info.src_dir info in
+      get sctx ~dir
+    in
+    ocaml t
+  in
+  let sentinel =
+    let lib = Lib.Local.to_lib lib in
+    Lib.sentinel lib
   in
-  let name = Lib_info.name info in
-  ocaml t >>| Ml_sources.modules ~for_:(Library name)
+  Ml_sources.modules sources ~for_:(Library sentinel)
 ;;
 
 let modules_of_lib sctx lib =

src/dune_rules/dune_package.ml

@@ -228,6 +228,9 @@ module Lib = struct
        let entry_modules = Modules.entry_modules modules |> List.map ~f:Module.name in
        let info : Path.t Lib_info.t =
          let src_dir = Obj_dir.dir obj_dir in
+         let sentinel =
+           Lib_info.Sentinel.external_ ~loc ~src_dir ~enabled_if:Blang.true_ name
+         in
          let enabled = Memo.return Lib_info.Enabled_status.Normal in
          let status =
            match Lib_name.analyze name with
@@ -252,6 +255,7 @@ module Lib = struct
            ~path_kind:External
            ~loc
            ~name
+           ~sentinel
            ~kind
            ~status
            ~src_dir
@@ -358,12 +362,12 @@ end
 module Entry = struct
   type t =
     | Library of Lib.t
-    | Deprecated_library_name of Deprecated_library_name.t
+    | Deprecated_library_name of Path.t * Deprecated_library_name.t
     | Hidden_library of Lib.t
 
   let name = function
     | Library lib | Hidden_library lib -> Lib_info.name (Lib.info lib)
-    | Deprecated_library_name d -> d.old_public_name
+    | Deprecated_library_name (_, d) -> d.old_public_name
   ;;
 
   let version = function
@@ -373,7 +377,14 @@ module Entry = struct
 
   let loc = function
     | Library lib | Hidden_library lib -> Lib_info.loc (Lib.info lib)
-    | Deprecated_library_name d -> d.loc
+    | Deprecated_library_name (_, d) -> d.loc
+  ;;
+
+  let sentinel = function
+    | Library lib | Hidden_library lib ->
+      let info = Lib.info lib in
+      Lib_info.sentinel info
+    | Deprecated_library_name _ -> assert false
   ;;
 
   let cstrs ~lang ~dir =
@@ -383,15 +394,15 @@ module Entry = struct
         Library lib )
     ; ( "deprecated_library_name"
       , let+ x = Deprecated_library_name.decode in
-        Deprecated_library_name x )
+        Deprecated_library_name (dir, x) )
     ]
   ;;
 
   let to_dyn x =
     let open Dyn in
     match x with
     | Library lib -> variant "Library" [ Lib.to_dyn lib ]
-    | Deprecated_library_name lib ->
+    | Deprecated_library_name (_, lib) ->
       variant "Deprecated_library_name" [ Deprecated_library_name.to_dyn lib ]
     | Hidden_library lib -> variant "Hidden_library" [ Lib.to_dyn lib ]
   ;;
@@ -516,7 +527,7 @@ let encode ~dune_version { entries; name; version; dir; sections; sites; files }
       match e with
       | Entry.Library lib ->
         list (Dune_lang.atom "library" :: Lib.encode lib ~package_root:dir ~stublibs)
-      | Deprecated_library_name d ->
+      | Deprecated_library_name (_, d) ->
         list (Dune_lang.atom "deprecated_library_name" :: Deprecated_library_name.encode d)
       | Hidden_library lib ->
         Code_error.raise

src/dune_rules/dune_package.mli

@@ -42,7 +42,7 @@ end
 module Entry : sig
   type t =
     | Library of Lib.t
-    | Deprecated_library_name of Deprecated_library_name.t
+    | Deprecated_library_name of Path.t * Deprecated_library_name.t
     | Hidden_library of Lib.t
     (** Only for external libraries that:
 
@@ -53,6 +53,7 @@ module Entry : sig
         Dune itself never produces hidden libraries. *)
 
   val name : t -> Lib_name.t
+  val sentinel : t -> Lib_info.Sentinel.t
   val version : t -> Package_version.t option
   val loc : t -> Loc.t
   val to_dyn : t Dyn.builder

src/dune_rules/expander.ml

@@ -402,7 +402,7 @@ let expand_lib_variable t source ~lib ~file ~lib_exec ~lib_private =
       then Resolve.Memo.map p ~f:(fun _ -> assert false)
       else
         let open Resolve.Memo.O in
-        Lib.DB.available (Scope.libs scope) lib
+        Lib.DB.available_by_name (Scope.libs scope) lib
         |> Resolve.Memo.lift_memo
         >>= function
         | false ->
@@ -653,7 +653,7 @@ let expand_pform_macro
           (let lib = Lib_name.parse_string_exn (Dune_lang.Template.Pform.loc source, s) in
            let open Memo.O in
            let* scope = t.scope in
-           let+ available = Lib.DB.available (Scope.libs scope) lib in
+           let+ available = Lib.DB.available_by_name (Scope.libs scope) lib in
            available |> string_of_bool |> string))
   | Bin_available ->
     Need_full_expander

src/dune_rules/findlib.ml

@@ -23,10 +23,11 @@ end
 let builtin_for_dune : Dune_package.t =
   let entry =
     Dune_package.Entry.Deprecated_library_name
-      { loc = Loc.of_pos __POS__
-      ; old_public_name = Lib_name.of_string "dune.configurator"
-      ; new_public_name = Lib_name.of_string "dune-configurator"
-      }
+      ( Path.external_ Path.External.initial_cwd
+      , { loc = Loc.of_pos __POS__
+        ; old_public_name = Lib_name.of_string "dune.configurator"
+        ; new_public_name = Lib_name.of_string "dune-configurator"
+        } )
   in
   { name = Opam_package.Name.of_string "dune"
   ; entries = Lib_name.Map.singleton (Dune_package.Entry.name entry) entry
@@ -206,10 +207,16 @@ let to_dune_library (t : Findlib.Package.t) ~dir_contents ~ext_lib ~external_loc
                     | Error e -> Error e))))
     in
     let modules = Lib_info.Source.External None in
+    let name = t.name in
+    let sentinel =
+      let enabled_if = Blang.true_ in
+      Lib_info.Sentinel.external_ ~loc ~src_dir ~enabled_if name
+    in
     Lib_info.create
       ~loc
       ~path_kind:External
-      ~name:t.name
+      ~name
+      ~sentinel
       ~kind
       ~status
       ~src_dir

src/dune_rules/gen_meta.ml

@@ -163,7 +163,7 @@ let gen ~(package : Package.t) ~add_directory_entry entries =
   let+ pkgs =
     Memo.parallel_map entries ~f:(fun (e : Scope.DB.Lib_entry.t) ->
       match e with
-      | Library lib ->
+      | Library (_, lib) ->
         let info = Lib.Local.info lib in
         let pub_name =
           let name = Lib_info.name info in

src/dune_rules/gen_rules.ml

@@ -111,7 +111,10 @@ end = struct
       let+ () = Toplevel.Stanza.setup ~sctx ~dir ~toplevel in
       empty_none
     | Library.T lib ->
-      let* enabled_if = Lib.DB.available (Scope.libs scope) (Library.best_name lib) in
+      let* enabled_if =
+        let sentinel = Library.to_sentinel ~src_dir lib in
+        Lib.DB.available (Scope.libs scope) sentinel
+      in
       if_available_buildable
         ~loc:lib.buildable.loc
         (fun () -> Lib_rules.rules lib ~sctx ~dir ~scope ~dir_contents ~expander)

src/dune_rules/install_rules.ml

@@ -85,10 +85,10 @@ end = struct
       >>| List.singleton
   ;;
 
-  let lib_files ~dir_contents ~dir ~lib_config lib =
+  let lib_files ~dir_contents ~dir ~lib_config ~sentinel lib =
     let+ modules =
       let+ ml_sources = Dir_contents.ocaml dir_contents in
-      Some (Ml_sources.modules ml_sources ~for_:(Library (Lib_info.name lib)))
+      Some (Ml_sources.modules ml_sources ~for_:(Library sentinel))
     and+ foreign_archives =
       match Lib_info.virtual_ lib with
       | None -> Memo.return (Mode.Map.Multi.to_flat_list @@ Lib_info.foreign_archives lib)
@@ -179,9 +179,13 @@ end = struct
         ~lib_config
     in
     let lib_name = Library.best_name lib in
+    let sentinel =
+      let src_dir = Path.drop_optional_build_context_src_exn (Path.build dir) in
+      Library.to_sentinel ~src_dir lib
+    in
     let* installable_modules =
       let+ modules =
-        Dir_contents.ocaml dir_contents >>| Ml_sources.modules ~for_:(Library lib_name)
+        Dir_contents.ocaml dir_contents >>| Ml_sources.modules ~for_:(Library sentinel)
       and+ impl = Virtual_rules.impl sctx ~lib ~scope in
       Vimpl.impl_modules impl modules |> Modules.split_by_lib
     in
@@ -305,7 +309,7 @@ end = struct
           if Module.kind m = Virtual then [] else common m |> set_dir m)
       in
       modules_vlib @ modules_impl
-    and+ lib_files = lib_files ~dir ~dir_contents ~lib_config info
+    and+ lib_files = lib_files ~dir ~dir_contents ~lib_config ~sentinel info
     and+ execs = lib_ppxs ctx ~scope ~lib
     and+ dll_files =
       dll_files ~modes:ocaml ~dynlink:lib.dynlink ~ctx info
@@ -330,15 +334,20 @@ end = struct
       ]
   ;;
 
-  let keep_if expander ~scope stanza =
+  let keep_if ~expander ~scope ~dir stanza =
     let+ keep =
       match Stanza.repr stanza with
       | Library.T lib ->
         let* enabled_if = Expander.eval_blang expander lib.enabled_if in
         if enabled_if
         then
           if lib.optional
-          then Lib.DB.available (Scope.libs scope) (Library.best_name lib)
+          then (
+            let sentinel =
+              let src_dir = Path.drop_optional_build_context_src_exn (Path.build dir) in
+              Library.to_sentinel ~src_dir lib
+            in
+            Lib.DB.available (Scope.libs scope) sentinel)
           else Memo.return true
         else Memo.return false
       | Documentation.T _ -> Memo.return true
@@ -448,7 +457,7 @@ end = struct
   ;;
 
   let stanza_to_entries ~package_db ~sctx ~dir ~scope ~expander stanza =
-    (let+ stanza = keep_if expander stanza ~scope in
+    (let+ stanza = keep_if ~expander ~scope ~dir stanza in
      let open Option.O in
      let* stanza = stanza in
      let+ package = Stanzas.stanza_package stanza in
@@ -620,8 +629,8 @@ end = struct
             (Some
                ( old_public_name
                , Dune_package.Entry.Deprecated_library_name
-                   { loc; old_public_name; new_public_name } ))
-        | Library lib ->
+                   (Path.build pkg_root, { loc; old_public_name; new_public_name }) ))
+        | Library (sentinel, lib) ->
           let info = Lib.Local.info lib in
           let dir = Lib_info.src_dir info in
           let* dir_contents = Dir_contents.get sctx ~dir in
@@ -653,7 +662,8 @@ end = struct
             |> Foreign.Sources.object_files ~dir ~ext_obj
             |> List.map ~f:Path.build
           and* modules =
-            Dir_contents.ocaml dir_contents >>| Ml_sources.modules ~for_:(Library name)
+            Dir_contents.ocaml dir_contents
+            >>| Ml_sources.modules ~for_:(Library sentinel)
           and* melange_runtime_deps = file_deps (Lib_info.melange_runtime_deps info)
           and* public_headers = file_deps (Lib_info.public_headers info) in
           let+ dune_lib =
@@ -730,6 +740,9 @@ end = struct
         acc
         >>>
         let dune_pkg =
+          let dir =
+            Path.build (Install.Context.lib_dir ~context:ctx.name ~package:name)
+          in
           let entries =
             match Package.Name.Map.find deprecated_dune_packages name with
             | None -> Lib_name.Map.empty
@@ -751,13 +764,13 @@ end = struct
                     acc
                     old_public_name
                     (Dune_package.Entry.Deprecated_library_name
-                       { loc; old_public_name; new_public_name }))
+                       (dir, { loc; old_public_name; new_public_name })))
           in
           let sections = sections ctx.name [] pkg in
           { Dune_package.version = Package.version pkg
           ; name
           ; entries
-          ; dir = Path.build (Install.Context.lib_dir ~context:ctx.name ~package:name)
+          ; dir
           ; sections
           ; sites = Package.sites pkg
           ; files = []
@@ -798,7 +811,7 @@ end = struct
           let* () = Action_builder.return () in
           match
             List.find_map entries ~f:(function
-              | Library lib ->
+              | Library (_, lib) ->
                 let info = Lib.Local.info lib in
                 Option.some_if (Option.is_some (Lib_info.virtual_ info)) lib
               | Deprecated_library_name _ -> None)