commit a9e9e3f7b4914ae1af50907a0b6af4e61ae518d4
from: Omar Polo <op@omarpolo.com>
date: Sat Aug 07 21:13:25 2021 UTC

add special instruction `vargs': yields the number of varargs

commit - c31f55f534c112abd2319b8b0de79878b39b775d
commit + a9e9e3f7b4914ae1af50907a0b6af4e61ae518d4
blob - 2dea90aca8c47690f4e37ac1c1dcdce3cf81d43e
blob + e2e994d9ceb6b0d5ddb002d96408cf19daea148d
--- script.c
+++ script.c
@@ -165,6 +165,16 @@ static inline void
 pushbool(int n)
 {
 	pushv(n ? &v_true : &v_false);
+}
+
+static inline void
+pushnum(int64_t n)
+{
+	struct value v;
+
+	v.type = V_NUM;
+	v.v.num = n;
+	pushv(&v);
 }
 
 static inline struct opstack *
@@ -494,7 +504,17 @@ op_sfail(struct op *expr, char *msg)
 	op = newop(OP_SFAIL);
 	op->v.sfail.expr = expr;
 	op->v.sfail.msg = msg;
+
+	return op;
+}
+
+struct op *
+op_vargs(void)
+{
+	struct op	*op;
 
+	op = newop(OP_VARGS);
+
 	return op;
 }
 
@@ -782,6 +802,9 @@ pp_op(struct op *op)
 		if (op->v.sfail.msg != NULL)
 			printf(": \"%s\"", op->v.sfail.msg);
 		break;
+	case OP_VARGS:
+		printf("vargs");
+		break;
 	default:
 		printf(" ???[%d] ", op->type);
 	}
@@ -975,6 +998,15 @@ eval(struct op *op)
 			return ret;
 		break;
 
+	case OP_VARGS:
+		if ((ret = getvar_raw("...", &t)) == EVAL_OK) {
+                        for (i = 0; t != NULL; t = t->next)
+				i++;
+			pushnum(i);
+		} else
+			pushnum(0);
+		break;
+
 	default:
 		before_printing();
 		fprintf(stderr, "invalid op, aborting.\n");