Refactor eval_string further into shell_eval_invocation and opam_env_…

…invocation

src/state/opamEnv.ml

@@ -334,17 +334,31 @@ let is_up_to_date ?skip st =
   is_up_to_date_raw ?skip
     (updates ~set_opamroot:false ~set_opamswitch:false ~force_path:false st)
 
-(** The "simple" version of [eval_string] in the sense that it doesn't support
-    figuring out `opam env` arguments and requires passing any extra arguments
-    via [suffix]. *)
-let eval_string_simple ?(suffix="") shell =
+(** Returns shell-appropriate statement to evaluate [cmd]. *)
+let shell_eval_invocation shell cmd =
   match shell with
   | SH_fish ->
-    Printf.sprintf "eval (opam env%s)" suffix
+    Printf.sprintf "eval (%s)" cmd
   | SH_csh ->
-    Printf.sprintf "eval `opam env%s`" suffix
+    Printf.sprintf "eval `%s`" cmd
   | _ ->
-    Printf.sprintf "eval $(opam env%s)" suffix
+    Printf.sprintf "eval $(%s)" cmd
+
+(** Returns "opam env" invocation string together with optional root and switch
+    overrides *)
+let opam_env_invocation ?root ?switch ?(set_opamswitch=false) () =
+  let root =
+    match root with
+    | None -> ""
+    | Some r -> Printf.sprintf " --root=%s" r
+  in
+  let switch =
+    match switch with
+    | None -> ""
+    | Some s -> Printf.sprintf " --switch=%s" s
+  in
+  let setswitch = if set_opamswitch then " --set-switch" else "" in
+  Printf.sprintf "opam env%s%s%s" root switch setswitch
 
 let eval_string gt ?(set_opamswitch=false) switch =
   let root =
@@ -355,12 +369,13 @@ let eval_string gt ?(set_opamswitch=false) switch =
         OpamFilename.Dir.to_string OpamStateConfig.(default.root_dir)
       ) in
     if opamroot_cur <> opamroot_env then
-      Printf.sprintf " --root=%s" opamroot_cur
+      Some opamroot_cur
     else
-      "" in
+      None
+  in
   let switch =
     match switch with
-    | None -> ""
+    | None -> None
     | Some sw ->
       let sw_cur = OpamSwitch.to_string sw in
       let sw_env =
@@ -371,13 +386,10 @@ let eval_string gt ?(set_opamswitch=false) switch =
           (OpamFile.Config.switch gt.config >>| OpamSwitch.to_string)
         )
       in
-      if Some sw_cur <> sw_env then Printf.sprintf " --switch=%s" sw_cur
-      else ""
+      if Some sw_cur <> sw_env then Some sw_cur else None
   in
-  let setswitch = if set_opamswitch then " --set-switch" else "" in
   let shell = OpamStd.Sys.guess_shell_compat () in
-  let suffix = root ^ switch ^ setswitch in
-  eval_string_simple ~suffix shell
+  shell_eval_invocation shell (opam_env_invocation ?root ?switch ~set_opamswitch ())
 
 
 (* -- Shell and init scripts handling -- *)
@@ -706,7 +718,7 @@ let setup
         (OpamConsole.colorise `bold @@ string_of_shell shell)
         (OpamConsole.colorise `cyan @@ OpamFilename.prettify dot_profile)
         (OpamConsole.colorise `bold @@ source root shell (init_file shell))
-        (OpamConsole.colorise `bold @@ eval_string_simple shell);
+        (OpamConsole.colorise `bold @@ shell_eval_invocation shell (opam_env_invocation ()));
       if OpamCoreConfig.(!r.answer = Some true) then begin
         OpamConsole.warning "Shell not updated in non-interactive mode: use --shell-setup";
         None