Added heuristic for passing arg via responsefiles.

Since gnu make and other tools under windows seem to have a limit
of around 8000 bytes per command line the arguments should be
passed via responsefiles instead.
Bug 18308

1 files changed, 7 insertions, 2 deletions

diff --git a/driver/Frontend.ml b/driver/Frontend.ml
index 043d4e5a..41b09b58 100644
--- a/driver/Frontend.ml
+++ b/driver/Frontend.ml
@@ -24,8 +24,11 @@ open Printf
 let preprocess ifile ofile =
   let output =
     if ofile = "-" then None else Some ofile in
-  let cmd = List.concat [
-    Configuration.prepro;
+  let cmd,opts = match Configuration.prepro with
+  | name::opts -> name,opts
+  | [] -> assert false (* Should be catched in Configuration *) in
+  let opts = List.concat [
+    opts;
     ["-D__COMPCERT__"];
     (if !Clflags.use_standard_headers
      then ["-I" ^ Filename.concat !Clflags.stdlib_path "include" ]
@@ -33,6 +36,8 @@ let preprocess ifile ofile =
     List.rev !prepro_options;
     [ifile]
   ] in
+  let opts = responsefile opts (fun a -> if gnu_system then ["@"^a] else ["@"^a]) in
+  let cmd = cmd::opts in
   let exc = command ?stdout:output cmd in
   if exc <> 0 then begin
     if ofile <> "-" then safe_remove ofile;