vvp: fix regression in behaviour of -N option (issue #1138)

The -N option was broken by PR #1068. This fix modifies and simplifies
the libvvp API that was introduced in that PR.

vvp/lib_main.cc

@@ -59,18 +59,13 @@ bool verbose_flag = false;
 static int vvp_return_value = 0;
 static int vvp_used = 0;
 
-void vvp_set_stop_is_finish(bool flag)
+void vvp_set_stop_is_finish(bool flag, int exit_code)
 {
       extern bool stop_is_finish;
-
-      stop_is_finish = flag;
-}
-
-void vvp_set_stop_is_finish_exit_code(bool flag)
-{
       extern int  stop_is_finish_exit_code;
 
-      stop_is_finish_exit_code = flag;
+      stop_is_finish = flag;
+      stop_is_finish_exit_code = exit_code;
 }
 
 void vvp_set_verbose_flag(bool flag)

vvp/libvvp.h

@@ -13,19 +13,19 @@ extern "C" {
 
 #include <stdbool.h>
 
-/* The first three functions may be called at any time.
- * vvp_set_stop_is_finish(true) is equivalent to vvp's "-n" option.
+/* vvp_set_stop_is_finish(true, 0) is equivalent to vvp's "-n" option.
+ * vvp_set_stop_is_finish(true, 1) is equivalent to vvp's "-N" option.
+ *
+ * This function may be called at any time.
  */
 
-extern void vvp_set_stop_is_finish(bool flag);
+extern void vvp_set_stop_is_finish(bool flag, int exit_code);
 
-/* vvp_set_stop_is_finish_exit_code(true) is equivalent to vvp's "-N" option.
+/* vvp_set_verbose(true) is equivalent to vvp's "-v" option.
+ *
+ * This function may be called at any time.
  */
 
-extern void vvp_set_stop_is_finish_exit_code(bool flag);
-
-/* vvp_set_verbose(true) is equivalent to vvp's "-v" option. */
-
 extern void vvp_set_verbose_flag(bool flag);
 
 /* vvp_no_signals() may be called at any time before vvp_run() to prevent

vvp/main.cc

@@ -87,10 +87,10 @@ int main(int argc, char*argv[])
 	    module_tab[module_cnt++] = optarg;
 	    break;
 	  case 'n':
-	    vvp_set_stop_is_finish(true);
+	    vvp_set_stop_is_finish(true, 0);
 	    break;
           case 'N':
-            vvp_set_stop_is_finish_exit_code(true);
+            vvp_set_stop_is_finish(true, 1);
             break;
 	  case 's':
 	    schedule_stop(0);

vvp/stop.cc

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003-2018 Stephen Williams ([email protected])
+ * Copyright (c) 2003-2024 Stephen Williams ([email protected])
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -41,7 +41,7 @@
 # include  "ivl_alloc.h"
 
 __vpiScope*stop_current_scope = 0;
-bool stop_is_finish;  /* When set, $stop acts like $finish (set in main.cc). */
+bool stop_is_finish = false;  /* When set, $stop acts like $finish (set in main.cc). */
 int  stop_is_finish_exit_code = 0;
 
 #ifndef USE_READLINE