Change echo to be variadic

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

src/action.ml

@@ -34,7 +34,7 @@ struct
       ; cstr "ignore-stderr"   (t @> nil)      (fun t -> Ignore (Stderr, t))
       ; cstr "ignore-outputs"  (t @> nil)      (fun t -> Ignore (Outputs, t))
       ; cstr "progn"           (rest t)        (fun l -> Progn l)
-      ; cstr "echo"           (string @> nil)         (fun x -> Echo x)
+      ; cstr "echo"      (string @> rest string) (fun x xs -> Echo (x::xs))
       ; cstr "cat"            (path @> nil)         (fun x -> Cat x)
       ; cstr "copy" (path @> path @> nil)              (fun src dst -> Copy (src, dst))
       (*
@@ -78,7 +78,8 @@ struct
            ]
     | Progn l -> List (Sexp.unsafe_atom_of_string "progn"
                        :: List.map l ~f:sexp_of_t)
-    | Echo x -> List [Sexp.unsafe_atom_of_string "echo"; string x]
+    | Echo xs ->
+      List (Sexp.unsafe_atom_of_string "echo" :: List.map xs ~f:string)
     | Cat x -> List [Sexp.unsafe_atom_of_string "cat"; path x]
     | Copy (x, y) ->
       List [Sexp.unsafe_atom_of_string "copy"; path x; path y]
@@ -150,7 +151,7 @@ module Make_mapper
     | Ignore (outputs, t) ->
       Ignore (outputs, map t ~dir ~f_program ~f_string ~f_path)
     | Progn l -> Progn (List.map l ~f:(fun t -> map t ~dir ~f_program ~f_string ~f_path))
-    | Echo x -> Echo (f_string ~dir x)
+    | Echo xs -> Echo (List.map xs ~f:(f_string ~dir))
     | Cat x -> Cat (f_path ~dir x)
     | Copy (x, y) -> Copy (f_path ~dir x, f_path ~dir y)
     | Symlink (x, y) ->
@@ -365,7 +366,7 @@ module Unexpanded = struct
       | Ignore (outputs, t) ->
         Ignore (outputs, expand t ~dir ~map_exe ~f)
       | Progn l -> Progn (List.map l ~f:(fun t -> expand t ~dir ~map_exe ~f))
-      | Echo x -> Echo (E.string ~dir ~f x)
+      | Echo xs -> Echo (List.map xs ~f:(E.string ~dir ~f))
       | Cat x -> Cat (E.path ~dir ~f x)
       | Copy (x, y) ->
         Copy (E.path ~dir ~f x, E.path ~dir ~f y)
@@ -457,7 +458,7 @@ module Unexpanded = struct
     | Ignore (outputs, t) ->
       Ignore (outputs, partial_expand t ~dir ~map_exe ~f)
     | Progn l -> Progn (List.map l ~f:(fun t -> partial_expand t ~dir ~map_exe ~f))
-    | Echo x -> Echo (E.string ~dir ~f x)
+    | Echo xs -> Echo (List.map xs ~f:(E.string ~dir ~f))
     | Cat x -> Cat (E.path ~dir ~f x)
     | Copy (x, y) ->
       Copy (E.path ~dir ~f x, E.path ~dir ~f y)
@@ -674,6 +675,11 @@ let exec_echo stdout_to str =
      | None -> print_string str; flush stdout
      | Some (_, oc) -> output_string oc str)
 
+let concat = function
+  | [] -> ""
+  | [x] -> x
+  | xs -> String.concat ~sep:"" xs
+
 let rec exec t ~ectx ~dir ~env ~stdout_to ~stderr_to =
   match t with
   | Run (Error e, _) ->
@@ -686,7 +692,7 @@ let rec exec t ~ectx ~dir ~env ~stdout_to ~stderr_to =
     exec t ~ectx ~dir ~stdout_to ~stderr_to
       ~env:(Env.add env ~var ~value)
   | Redirect (Stdout, fn, Echo s) ->
-    Io.write_file fn s;
+    Io.write_file fn (concat s);
     Fiber.return ()
   | Redirect (outputs, fn, Run (Ok prog, args)) ->
     let out = Process.File fn in
@@ -703,7 +709,7 @@ let rec exec t ~ectx ~dir ~env ~stdout_to ~stderr_to =
     redirect ~ectx ~dir outputs Config.dev_null t ~env ~stdout_to ~stderr_to
   | Progn l ->
     exec_list l ~ectx ~dir ~env ~stdout_to ~stderr_to
-  | Echo str -> exec_echo stdout_to str
+  | Echo strs -> exec_echo stdout_to (concat strs)
   | Cat fn ->
     Io.with_file_in fn ~f:(fun ic ->
       let oc =

src/action_intf.ml

@@ -29,7 +29,7 @@ module type Ast = sig
     | Redirect       of Outputs.t * path * t
     | Ignore         of Outputs.t * t
     | Progn          of t list
-    | Echo           of string
+    | Echo           of string list
     | Cat            of path
     | Copy           of path * path
     | Symlink        of path * path
@@ -61,7 +61,7 @@ module type Helpers = sig
   val ignore_stderr : t -> t
   val ignore_outputs : t -> t
   val progn : t list -> t
-  val echo : string -> t
+  val echo : string list -> t
   val cat : path -> t
   val copy : path -> path -> t
   val symlink : path -> path -> t