return the process return code along with the process outputs

--- a/src/HOL/Tools/SMT/smt_solver.ML	Mon Nov 08 12:13:44 2010 +0100
+++ b/src/HOL/Tools/SMT/smt_solver.ML	Mon Nov 08 12:13:51 2010 +0100
@@ -108,7 +108,11 @@
 
 fun run ctxt cmd args input =
   (case C.certificates_of ctxt of
-    NONE => Cache_IO.run (make_cmd (choose cmd) args) input
+    NONE =>
+      let
+        val {output, redirected_output, ...} =
+          Cache_IO.run (make_cmd (choose cmd) args) input
+      in (redirected_output, output) end 
   | SOME certs =>
       (case Cache_IO.lookup certs input of
         (NONE, key) =>

--- a/src/Tools/cache_io.ML	Mon Nov 08 12:13:44 2010 +0100
+++ b/src/Tools/cache_io.ML	Mon Nov 08 12:13:51 2010 +0100
@@ -6,10 +6,13 @@
 
 signature CACHE_IO =
 sig
+  (*IO wrapper*)
   val with_tmp_file: string -> (Path.T -> 'a) -> 'a
   val with_tmp_dir: string -> (Path.T -> 'a) -> 'a
-  val run: (Path.T -> Path.T -> string) -> string -> string list * string list
+  val run: (Path.T -> Path.T -> string) -> string ->
+    {output: string list, redirected_output: string list, return_code: int}
 
+  (*cache*)
   type cache
   val make: Path.T -> cache
   val cache_path_of: cache -> Path.T
@@ -23,6 +26,8 @@
 structure Cache_IO : CACHE_IO =
 struct
 
+(* IO wrapper *)
+
 val cache_io_prefix = "cache-io-"
 
 fun with_tmp_file name f =
@@ -45,21 +50,20 @@
   with_tmp_file cache_io_prefix (fn out_path =>
     let
       val _ = File.write in_path str
-      val (out2, _) = bash_output (make_cmd in_path out_path)
+      val (out2, rc) = bash_output (make_cmd in_path out_path)
       val out1 = the_default [] (try (rev o File.fold_lines cons out_path) [])
-    in (out1, split_lines out2) end))
+    in {output=split_lines out2, redirected_output=out1, return_code=rc} end))
 
 
+(* cache *)
 
 abstype cache = Cache of {
   path: Path.T,
   table: (int * (int * int * int) Symtab.table) Synchronized.var }
 with
 
-
 fun cache_path_of (Cache {path, ...}) = path
 
-
 fun load cache_path =
   let
     fun err () = error ("Cache IO: corrupted cache file: " ^
@@ -87,7 +91,6 @@
   let val table = if File.exists path then load path else (1, Symtab.empty)
   in Cache {path=path, table=Synchronized.var (Path.implode path) table} end
 
-
 fun load_cached_result cache_path (p, len1, len2) =
   let
     fun load line (i, xsp) =
@@ -97,7 +100,6 @@
       else (i, xsp)
   in pairself rev (snd (File.fold_lines load cache_path (1, ([], [])))) end
 
-
 fun lookup (Cache {path=cache_path, table}) str =
   let val key = SHA1.digest str
   in
@@ -106,10 +108,10 @@
     | SOME pos => (SOME (load_cached_result cache_path pos), key))
   end
 
-
 fun run_and_cache (Cache {path=cache_path, table}) key make_cmd str =
   let
-    val res as (out, err) = run make_cmd str
+    val {output=err, redirected_output=out, ...} = run make_cmd str
+    val res = (out, err)
     val (l1, l2) = pairself length res
     val header = key ^ " " ^ string_of_int l1 ^ " " ^ string_of_int l2
     val lines = map (suffix "\n") (header :: out @ err)
@@ -121,11 +123,11 @@
         in (p+l1+l2+1, Symtab.update (key, (p+1, l1, l2)) tab) end)
   in res end
 
-
 fun run_cached cache make_cmd str =
   (case lookup cache str of
     (NONE, key) => run_and_cache cache key make_cmd str
   | (SOME output, _) => output)
 
 end
+
 end