Add parallel parsing (issue #589)

src/dune

@@ -8,7 +8,7 @@
   (public_name goblint.lib)
   (wrapped false)
   (modules :standard \ goblint mainarinc mainspec privPrecCompare apronPrecCompare)
-  (libraries goblint.sites goblint-cil.all-features batteries.unthreaded qcheck-core.runner sha json-data-encoding jsonrpc cpu
+  (libraries goblint.sites goblint-cil.all-features batteries.unthreaded qcheck-core.runner sha json-data-encoding jsonrpc cpu parmap
     ; Conditionally compile based on whether apron optional dependency is installed or not.
     ; Alternative dependencies seem like the only way to optionally depend on optional dependencies.
     ; See: https://dune.readthedocs.io/en/stable/concepts.html#alternative-dependencies.

src/maingoblint.ml

@@ -292,12 +292,17 @@ let merge_preprocessed cpp_file_names =
   (* get the AST *)
   if get_bool "dbg.verbose" then print_endline "Parsing files.";
   let get_ast_and_record_deps f =
-    let file = Cilfacade.getAST f in
-    (* Drop <built-in> and <command-line> from dependencies *)
-    Hashtbl.add Preprocessor.dependencies f @@ List.filter (fun (n,_) -> n <> "<built-in>" && n <> "<command-line>") file.files;
-    file
+    Cilfacade.getAST f
   in
-  let files_AST = List.map (get_ast_and_record_deps) cpp_file_names in
+  (* let files_AST = Parmap.parmap ~ncores:(Goblintutil.jobs ()) (get_ast_and_record_deps) (L cpp_file_names) in *)
+  let files_AST = List.map (get_ast_and_record_deps) (cpp_file_names) in
+
+  List.iter2 (fun f file ->
+      (* Drop <built-in> and <command-line> from dependencies *)
+      Hashtbl.add Preprocessor.dependencies f @@ List.filter (fun (n,_) -> n <> "<built-in>" && n <> "<command-line>") file.Cil.files;
+    ) cpp_file_names files_AST;
+
+  (* raise Exit; *)
 
   let cilout =
     if get_string "dbg.cilout" = "" then Legacy.stderr else Legacy.open_out (get_string "dbg.cilout")