Coccinelle release 1.0.0-rc13

[bpt/coccinelle.git] / bundles / menhirLib / menhir-20120123 / demos / ocamldep.wrapper

diff --git a/bundles/menhirLib/menhir-20120123/demos/ocamldep.wrapper b/bundles/menhirLib/menhir-20120123/demos/ocamldep.wrapper
new file mode 100755 (executable)
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+++ b/bundles/menhirLib/menhir-20120123/demos/ocamldep.wrapper
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+#!/usr/bin/env ocaml
+
+(* ocamldep.wrapper <filename> ... <filename> - <ocamldep command>
+   runs the <ocamldep command> in an environment where all of the
+   <filenames> listed appear to exist. The files are created, if
+   required, before the command is run, and destroyed afterwards. *)
+
+(* An earlier version of this script acquired a lock, so as to prevent
+   multiple instances of this script from interfering with one another.
+   However, this did not prevent interference between this script and
+   some other process (e.g., the ocaml compiler) which creates files.
+   So, the lock has been removed. My suggestion is to never use this
+   script in a concurrent setting. If you wish to use parallel make,
+   then you might be able to use a two-level Makefile approach: first,
+   compute all dependencies in a sequential manner; then, construct all
+   targets in a parallel manner. *)
+
+#load "unix.cma"
+open Printf
+
+(* Parse the command line. The arguments that precede "-" are understood
+   as file names and stored in the list [xs]. The arguments that follow
+   "-" are understood as a command and stored in [command]. *)
+
+let xs =
+  ref []
+
+let command =
+  ref ""
+
+let verbose =
+  ref false
+
+let rec loop accumulating i =
+  if i = Array.length Sys.argv then
+    ()
+  else if accumulating then
+    (* [accumulating] is [true] as long as we have not found the "-" marker *)
+    match Sys.argv.(i) with
+    | "-v" ->
+       verbose := true;
+       loop true (i+1)
+    | "-" ->
+        (* We have found the marker. The next parameter should be the name of
+          the raw [ocamldep] command. Copy it to the command (unquoted --
+          apparently some shells do not permit quoting a command name). *)
+       let i = i + 1 in
+       assert (i < Array.length Sys.argv);
+       command := Sys.argv.(i);
+       (* Stop accumulating file names. Copy the remaining arguments into
+          the command. *)
+       loop false (i+1)
+    | _ ->
+        (* Continue accumulating file names in [xs]. *)
+       xs := Sys.argv.(i) :: !xs;
+       loop true (i+1)
+  else begin
+    (* After we have found the "-" marker, the remaining arguments are
+       copied (quoted) into the command. *)
+    command := sprintf "%s %s" !command (Filename.quote Sys.argv.(i));
+    loop false (i+1)
+  end
+
+let () =
+  loop true 1
+
+(* Create the required files if they don't exist, run the command,
+   then destroy any files that we have created. *)
+
+let rec loop = function
+  | [] ->
+      if !verbose then
+       fprintf stderr "ocamldep.wrapper: running %s\n" !command;
+      Sys.command !command
+  | x :: xs ->
+      if Sys.file_exists x then
+       loop xs
+      else begin
+       if !verbose then
+         fprintf stderr "ocamldep.wrapper: creating fake %s\n" x;
+       let c = open_out x in
+       close_out c;
+       let exitcode = loop xs in
+       if Sys.file_exists x then begin
+         try
+           if !verbose then
+             fprintf stderr "ocamldep.wrapper: removing fake %s..." x;
+           Sys.remove x;
+           if !verbose then
+             fprintf stderr " ok\n"
+         with Sys_error _ ->
+           if !verbose then
+             fprintf stderr " failed\n"
+       end;
+       exitcode
+      end
+
+let () =
+  exit (loop !xs)