4 files changed, 33 insertions, 3 deletions

diff --git a/toplevel/opttoploop.ml b/toplevel/opttoploop.ml
index 86449bf681..6d6b5beb0d 100644
--- a/toplevel/opttoploop.ml
+++ b/toplevel/opttoploop.ml
@@ -565,6 +565,13 @@ let loop ppf =
 
 (* Execute a script.  If [name] is "", read the script from stdin. *)
 
+let override_sys_argv args =
+  let len = Array.length args in
+  if Array.length Sys.argv < len then invalid_arg "Toploop.override_sys_argv";
+  Array.blit args 0 Sys.argv 0 len;
+  Obj.truncate (Obj.repr Sys.argv) len;
+  Arg.current := 0
+
 let run_script ppf name args =
   let len = Array.length args in
   if Array.length Sys.argv < len then invalid_arg "Toploop.run_script";
diff --git a/toplevel/opttoploop.mli b/toplevel/opttoploop.mli
index 3ce4d19108..f234b4f4cf 100644
--- a/toplevel/opttoploop.mli
+++ b/toplevel/opttoploop.mli
@@ -120,3 +120,13 @@ val read_interactive_input : (string -> bytes -> int -> int * bool) ref
 (* Hooks for initialization *)
 
 val toplevel_startup_hook : (unit -> unit) ref
+
+(* Misc *)
+
+val override_sys_argv : string array -> unit
+(* [override_sys_argv args] replaces the contents of [Sys.argv] by [args]
+   and reset [Arg.current] to [0].
+
+   This is called by [run_script] so that [Sys.argv] represents
+   "script.ml args..." instead of the full command line:
+   "ocamlrun unix.cma ... script.ml args...". *)
diff --git a/toplevel/toploop.ml b/toplevel/toploop.ml
index a72c9ce63b..445eddd47e 100644
--- a/toplevel/toploop.ml
+++ b/toplevel/toploop.ml
@@ -539,12 +539,15 @@ let loop ppf =
 
 (* Execute a script.  If [name] is "", read the script from stdin. *)
 
-let run_script ppf name args =
+let override_sys_argv args =
   let len = Array.length args in
-  if Array.length Sys.argv < len then invalid_arg "Toploop.run_script";
+  if Array.length Sys.argv < len then invalid_arg "Toploop.override_sys_argv";
   Array.blit args 0 Sys.argv 0 len;
   Obj.truncate (Obj.repr Sys.argv) len;
-  Arg.current := 0;
+  Arg.current := 0
+
+let run_script ppf name args =
+  override_sys_argv args;
   Compmisc.init_path ~dir:(Filename.dirname name) true;
                    (* Note: would use [Filename.abspath] here, if we had it. *)
   begin
diff --git a/toplevel/toploop.mli b/toplevel/toploop.mli
index ba2f0c6d9b..7a478b3c34 100644
--- a/toplevel/toploop.mli
+++ b/toplevel/toploop.mli
@@ -145,3 +145,13 @@ val toplevel_startup_hook : (unit -> unit) ref
 (* Used by Trace module *)
 
 val may_trace : bool ref
+
+(* Misc *)
+
+val override_sys_argv : string array -> unit
+(* [override_sys_argv args] replaces the contents of [Sys.argv] by [args]
+   and reset [Arg.current] to [0].
+
+   This is called by [run_script] so that [Sys.argv] represents
+   "script.ml args..." instead of the full command line:
+   "ocamlrun unix.cma ... script.ml args...". *)