vm: add uc_vm_invoke() helper

The uc_vm_invoke() function simplifies calling a named ucode function with
arbitrary arguments.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

2 files changed, 33 insertions, 0 deletions

diff --git a/vm.c b/vm.c
index 24b2472..b05fbb7 100644
--- a/vm.c
+++ b/vm.c
@@ -2379,3 +2379,35 @@ uc_vm_scope_set(uc_vm *vm, uc_value_t *ctx)
 	ucv_put(vm->globals);
 	vm->globals = ctx;
 }
+
+uc_value_t *
+uc_vm_invoke(uc_vm *vm, const char *fname, size_t nargs, ...)
+{
+	uc_exception_type_t ex;
+	uc_value_t *fno, *arg;
+	va_list ap;
+	size_t i;
+
+	fno = ucv_property_get(vm->globals, fname);
+
+	if (!ucv_is_callable(fno))
+		return NULL;
+
+	uc_vm_stack_push(vm, ucv_get(fno));
+
+	va_start(ap, nargs);
+
+	for (i = 0; i < nargs; i++) {
+		arg = va_arg(ap, uc_value_t *);
+		uc_vm_stack_push(vm, ucv_get(arg));
+	}
+
+	va_end(ap);
+
+	ex = uc_vm_call(vm, false, nargs);
+
+	if (ex)
+		return NULL;
+
+	return uc_vm_stack_pop(vm);
+}
diff --git a/vm.h b/vm.h
index 2dae69d..5065ec6 100644
--- a/vm.h
+++ b/vm.h
@@ -125,5 +125,6 @@ void __attribute__((format(printf, 3, 0)))
 uc_vm_raise_exception(uc_vm *vm, uc_exception_type_t type, const char *fmt, ...);
 
 uc_vm_status_t uc_vm_execute(uc_vm *vm, uc_function_t *fn, uc_value_t *modules);
+uc_value_t *uc_vm_invoke(uc_vm *vm, const char *fname, size_t nargs, ...);
 
 #endif /* __VM_H_ */