Question about using Function-caller block

I used function-caller block at my work.

After code gen, I got some problem as below.

For example my fuction caller block is set as below.

Function prototype : y = GetValue() Output argument specifications : int8(0)

after code gen.

GetValue(&y);

I want result of code-gen is "y=GetValue();". Are there any way to make this?

Pleas let me know how to make it if possible.