[wp] -wp-par defaults to number of logical cores

src/plugins/wp/cores.c

+/**************************************************************************/
+/*                                                                        */
+/*  This file is part of Frama-C.                                         */
+/*                                                                        */
+/*  Copyright (C) 2007-2024                                               */
+/*    CEA (Commissariat à l'énergie atomique et aux énergies              */
+/*         alternatives)                                                  */
+/*                                                                        */
+/*  you can redistribute it and/or modify it under the terms of the GNU   */
+/*  Lesser General Public License as published by the Free Software       */
+/*  Foundation, version 2.1.                                              */
+/*                                                                        */
+/*  It is distributed in the hope that it will be useful,                 */
+/*  but WITHOUT ANY WARRANTY; without even the implied warranty of        */
+/*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         */
+/*  GNU Lesser General Public License for more details.                   */
+/*                                                                        */
+/*  See the GNU Lesser General Public License version 2.1                 */
+/*  for more details (enclosed in the file licenses/LGPLv2.1).            */
+/*                                                                        */
+/**************************************************************************/
+
+#include <caml/memory.h>
+#include <caml/mlvalues.h>
+
+#ifdef _WIN32
+#include <windows.h>
+#else
+#include <unistd.h>
+#endif
+
+int cores(void) {
+#ifdef WIN32
+  SYSTEM_INFO sysinfo;
+  GetSystemInfo(&sysinfo);
+  return sysinfo.dwNumberOfProcessors;
+#else
+  return sysconf(_SC_NPROCESSORS_CONF);
+#endif
+}
+
+CAMLprim value caml_cores(value unit) {
+  CAMLparam1(unit);
+  CAMLreturn(Val_int(cores()));
+}

src/plugins/wp/dune

@@ -44,6 +44,7 @@
     (select wp_eva.ml from
       (frama-c-eva.core -> wp_eva.enabled.ml)
       (  -> wp_eva.disabled.ml)))
+  (foreign_stubs (language c) (names cores))
   (instrumentation (backend landmarks))
   (instrumentation (backend bisect_ppx)))
 

src/plugins/wp/wp_parameters.ml

@@ -885,12 +885,14 @@ module TimeMargin =
          (default: %s)." default
   end)
 
+external cores : unit -> int = "caml_cores"
+
 let () = Parameter_customize.set_group wp_prover
 module Procs =
   Int(struct
     let option_name = "-wp-par"
     let arg_name = "p"
-    let default = 4
+    let default = cores ()
     let help =
       Printf.sprintf
         "Number of parallel proof process (default: %d)" default