snc: new option +p, if not active, throw error if pv function is called with multi-PV array

src/snc/gen_ss_code.c

@@ -660,7 +660,6 @@ static void gen_pv_func(
 	uint	num_extra_parms = 0;
 
 	ap = ep->func_args;
-	/* first parameter is always */
 	if (ap == 0)
 	{
 		error_at_expr(ep,
@@ -671,6 +670,16 @@ static void gen_pv_func(
 	if (ap->type == E_VAR)
 	{
 		vp = ap->extra.e_var;
+		if (vp->assign == M_MULTI && !global_options.newpv)
+		{
+			error_at_expr(ap,
+			  "1st argument '%s' to function '%s' must not be a multi-PV array\n",
+			  vp->name, func_name);
+			report_at_expr(ap, "Perhaps you meant %s[0]?\n", vp->name);
+			report_at_expr(ap, "Use option +p to allow this but then "
+			  "pv functions operate on all contained PVs\n");
+			return;
+		}
 	}
 	else if (ap->type == E_SUBSCR)
 	{

src/snc/main.c

@@ -182,6 +182,9 @@ static void parse_option(char *s)
 	case 'm':
 		options.main = opt_val;
 		break;
+	case 'p':
+		options.newpv = opt_val;
+		break;
 	case 's':
 		options.safe = opt_val;
 		break;

src/snc/types.h

@@ -70,9 +70,10 @@ struct options
 	uint	line:1;			/* generate line markers */
 	uint	warn:1;			/* compiler warnings */
 	uint	xwarn:1;		/* extra compiler warnings */
+	uint	newpv:1;		/* multi pv mode for builtin functions */
 };
 
-#define DEFAULT_OPTIONS {0,1,0,0,0,1,0,1,1,0}
+#define DEFAULT_OPTIONS {0,1,0,0,0,1,0,1,1,0,0}
 
 struct state_options			/* run-time state options */
 {