make Call_provers a bit more legible

src/driver/call_provers.ml

@@ -79,6 +79,10 @@ let call_prover command opt_cout buffer =
   Debug.dprintf debug "Call_provers: prover output:@\n%s@." out;
   ret, out, time
 
+type post_prover_call = unit -> prover_result
+
+type bare_prover_call = unit -> post_prover_call
+
 let call_on_buffer ~command ?(timelimit=0) ?(memlimit=0)
                    ~regexps ~exitcodes ~filename buffer =
   let on_stdin = ref true in
@@ -92,42 +96,36 @@ let call_on_buffer ~command ?(timelimit=0) ?(memlimit=0)
     | _ -> failwith "unknown format specifier, use %%f, %%t or %%m"
   in
   let cmd = Str.global_substitute cmd_regexp (replace "") command in
-  let f = if !on_stdin then
-    fun () -> call_prover cmd None buffer
-  else begin
-      let fout,cout = Filename.open_temp_file "why_" ("_" ^ filename) in
-      try
-        let cmd = Str.global_substitute cmd_regexp (replace fout) command in
-        fun () ->
-        let res = call_prover cmd (Some cout) buffer in
-        if Debug.nottest_flag debug then Sys.remove fout;
-        res
-      with e ->
-        close_out cout;
-        if Debug.nottest_flag debug then Sys.remove fout;
-        raise e
-    end
+  let on_stdin = !on_stdin in
+  let cmd,fout,cout = if on_stdin then cmd, "", None else
+    let fout,cout = Filename.open_temp_file "why_" ("_" ^ filename) in
+    let cmd =
+      try Str.global_substitute cmd_regexp (replace fout) command
+      with e -> close_out cout; Sys.remove fout; raise e
+    in
+    cmd, fout, Some cout
   in
   fun () ->
-    let ret,out,time = f () in
+    let ret,out,time = call_prover cmd cout buffer in
     fun () ->
-  let ans = match ret with
-    | Unix.WSTOPPED n ->
-        Debug.dprintf debug "Call_provers: stopped by signal %d@." n;
-        HighFailure
-    | Unix.WSIGNALED n ->
-        Debug.dprintf debug "Call_provers: killed by signal %d@." n;
-        HighFailure
-    | Unix.WEXITED n ->
-        Debug.dprintf debug "Call_provers: exited with status %d@." n;
-        (try List.assoc n exitcodes with Not_found -> grep out regexps)
-  in
-  let ans = match ans with
-    | HighFailure when !on_timelimit && timelimit > 0
-      && time >= (0.9 *. float timelimit) -> Timeout
-    | _ -> ans
-  in
-  { pr_answer = ans;
-    pr_output = out;
-    pr_time   = time }
+      if not on_stdin && Debug.nottest_flag debug then Sys.remove fout;
+      let ans = match ret with
+        | Unix.WSTOPPED n ->
+            Debug.dprintf debug "Call_provers: stopped by signal %d@." n;
+            HighFailure
+        | Unix.WSIGNALED n ->
+            Debug.dprintf debug "Call_provers: killed by signal %d@." n;
+            HighFailure
+        | Unix.WEXITED n ->
+            Debug.dprintf debug "Call_provers: exited with status %d@." n;
+            (try List.assoc n exitcodes with Not_found -> grep out regexps)
+      in
+      let ans = match ans with
+        | HighFailure when !on_timelimit && timelimit > 0
+          && time >= (0.9 *. float timelimit) -> Timeout
+        | _ -> ans
+      in
+      { pr_answer = ans;
+        pr_output = out;
+        pr_time   = time }
 

src/driver/call_provers.mli

@@ -52,11 +52,18 @@ val print_prover_result : Format.formatter -> prover_result -> unit
     a [HighFailure] *)
 
 val debug : Debug.flag
-(** debug flag for the calling procedure (option "--debug
-    call_prover")
+(** debug flag for the calling procedure (option "--debug call_prover")
     If set [call_on_buffer] prints on stderr the commandline called
-    and the output of the prover.
-*)
+    and the output of the prover. *)
+
+type post_prover_call = unit -> prover_result
+(** Thread-unsafe closure that processes a prover's output
+    and returns the final result. Once again: this closure
+    may use internal Why structures and is therefore not
+    thread-safe. *)
+
+type bare_prover_call = unit -> post_prover_call
+(** Thread-safe closure that executes a prover on a task. *)
 
 val call_on_buffer :
   command    : string ->
@@ -65,23 +72,22 @@ val call_on_buffer :
   regexps    : (Str.regexp * prover_answer) list ->
   exitcodes  : (int * prover_answer) list ->
   filename   : string ->
-  Buffer.t -> unit -> unit -> prover_result
+  Buffer.t -> bare_prover_call
 (** Call a prover on the task printed in the {!type: Buffer.t} given.
-    Only the computation between the two [unit] is parallelisable.
 
-    @param timelimit : set the available time limit (default 0 : unlimited)
-    @param memlimit : set the available time limit (default 0 :
-    unlimited)
+    @param timelimit : set the available time limit (def. 0 : unlimited)
+    @param memlimit : set the available time limit (def. 0 : unlimited)
+
+    @param regexps : if the first field matches the prover output,
+    the second field is the answer. Regexp groups present in
+    the first field are substituted in the second field (\0,\1,...).
+    The regexps are tested in the order of the list.
 
-    @param regexps : if the first field match the prover output the
-    second field is the answer. Regexp groups present in the first field are
-    substituted in the second field (\0,\1,...). The regexp are tested in the
-    order of the list.
-    @param exitcodes : if the first field is the exit code the second
-    field is the answer. No subtitution are done. Exit codes are tested
-    in the order of the list and before the regexps.
+    @param exitcodes : if the first field is the exit code, then
+    the second field is the answer. Exit codes are tested in the order
+    of the list and before the regexps.
 
     @param filename : if the prover doesn't accept stdin, a temporary
-    file is used. In the case the suffix of the temporary file is
-    [filename] *)
+    file is used. In this case the suffix of the temporary file is
+    [filename]. *)
 

src/driver/driver.mli

@@ -41,7 +41,7 @@ val call_on_buffer :
   command    : string ->
   ?timelimit : int ->
   ?memlimit  : int ->
-  driver -> Buffer.t -> unit -> unit -> Call_provers.prover_result
+  driver -> Buffer.t -> Call_provers.bare_prover_call
 
 val print_task :
   ?old       : in_channel ->
@@ -52,5 +52,5 @@ val prove_task :
   ?timelimit : int ->
   ?memlimit  : int ->
   ?old       : in_channel ->
-  driver -> Task.task -> (unit -> unit -> Call_provers.prover_result)
+  driver -> Task.task -> Call_provers.bare_prover_call