Use toplevel env stanza from workspace file

This should be the top most env stanza when it's available

Signed-off-by: Rudi Grinberg <rudi.grinberg@gmail.com>

src/context.ml

@@ -26,7 +26,7 @@ type t =
   ; for_host                : t option
   ; implicit                : bool
   ; build_dir               : Path.t
-  ; env_node                : Dune_env.Stanza.t option
+  ; env_nodes               : Dune_env.Stanza.t list
   ; path                    : Path.t list
   ; toplevel_path           : Path.t option
   ; ocaml_bin               : Path.t
@@ -131,7 +131,7 @@ let ocamlpath_sep =
   else
     Bin.path_sep
 
-let create ~(kind : Kind.t) ~path ~env ~env_node ~name ~merlin ~targets
+let create ~(kind : Kind.t) ~path ~env ~env_nodes ~name ~merlin ~targets
       ~profile () =
   let opam_var_cache = Hashtbl.create 128 in
   (match kind with
@@ -334,7 +334,7 @@ let create ~(kind : Kind.t) ~path ~env ~env_node ~name ~merlin ~targets
       ; kind
       ; profile
       ; merlin
-      ; env_node
+      ; env_nodes
       ; for_host = host
       ; build_dir
       ; path
@@ -410,11 +410,11 @@ let create ~(kind : Kind.t) ~path ~env ~env_node ~name ~merlin ~targets
 
 let opam_config_var t var = opam_config_var ~env:t.env ~cache:t.opam_var_cache var
 
-let default ?(merlin=true) ~env_node ~env ~targets () =
-  create ~kind:Default ~path:Bin.path ~env ~env_node ~name:"default"
+let default ?(merlin=true) ~env_nodes ~env ~targets () =
+  create ~kind:Default ~path:Bin.path ~env ~env_nodes ~name:"default"
     ~merlin ~targets ()
 
-let create_for_opam ?root ~env ~env_node ~targets ~profile ~switch ~name
+let create_for_opam ?root ~env ~env_nodes ~targets ~profile ~switch ~name
       ?(merlin=false) () =
   match Bin.opam with
   | None -> Utils.program_not_found "opam"
@@ -452,16 +452,26 @@ let create_for_opam ?root ~env ~env_node ~targets ~profile ~switch ~name
       | Some s -> Bin.parse_path s
     in
     let env = Env.extend env ~vars in
-    create ~kind:(Opam { root; switch }) ~profile ~targets ~path ~env ~env_node
+    create ~kind:(Opam { root; switch }) ~profile ~targets ~path ~env ~env_nodes
       ~name ~merlin ()
 
-let create ?merlin ~env def =
+let create ?merlin ?workspace_env ~env def =
+  let env_nodes =
+    match workspace_env with
+    | None -> Option.to_list
+    | Some s ->
+      begin function
+      | None -> [s]
+      | Some x -> [x; s]
+      end
+  in
   match (def : Workspace.Context.t) with
   | Default { targets; profile; env = env_node ; loc = _ } ->
-    default ~env ~env_node ~profile ~targets ?merlin ()
+    default ~env ~env_nodes:(env_nodes env_node) ~profile ~targets ?merlin ()
   | Opam { base = { targets ; profile ; env = env_node ; loc = _ }
          ; name; switch; root; merlin = _ } ->
-    create_for_opam ?root ~env_node ~env ~profile ~switch ~name ?merlin ~targets ()
+    create_for_opam ?root ~env_nodes:(env_nodes env_node) ~env ~profile
+      ~switch ~name ?merlin ~targets ()
 
 let which t s = which ~cache:t.which_cache ~path:t.path s
 

src/context.mli

@@ -51,7 +51,7 @@ type t =
     build_dir : Path.t
 
   ; (** env node that this context was initialized with *)
-    env_node : Dune_env.Stanza.t option
+    env_nodes : Dune_env.Stanza.t list
 
   ; (** [PATH] *)
     path : Path.t list
@@ -125,6 +125,7 @@ val compare : t -> t -> Ordering.t
 
 val create
   :  ?merlin:bool
+  -> ?workspace_env:Dune_env.Stanza.t
   -> env:Env.t
   -> Workspace.Context.t
   -> t list Fiber.t

src/super_context.ml

@@ -612,18 +612,24 @@ let create
     }
   in
   let context_env_node = lazy (
-    let config =
-      match context.env_node with
-      | Some s -> s
-      | None -> { loc = Loc.none; rules = [] }
+    let make ~inherit_from ~config =
+      { Env_node.
+        dir = context.build_dir
+      ; scope = Scope.DB.find_by_dir scopes context.build_dir
+      ; ocaml_flags = None
+      ; inherit_from
+      ; config
+      }
     in
-    { Env_node.
-      dir = context.build_dir
-    ; inherit_from = None
-    ; scope = Scope.DB.find_by_dir scopes context.build_dir
-    ; config
-    ; ocaml_flags = None
-    }
+    match context.env_nodes with
+    | [] ->
+      make ~config:{ loc = Loc.none; rules = [] } ~inherit_from:None
+    | [config] ->
+      make ~config ~inherit_from:None
+    | [context; workspace] ->
+      make ~config:context
+        ~inherit_from:(Some (lazy (make ~inherit_from:None ~config:workspace)))
+    | _::_::_::_ -> assert false
   ) in
   List.iter stanzas
     ~f:(fun { Dir_with_jbuild. ctx_dir; scope; stanzas; _ } ->