How to generate a warning if the macro called is not defined?

[Peng Yu]

Hi,

I call a macro that is not defined. It would not generate any error or
warnings. I looked at the manual section 8.6 "The `call' Function". I
don't see how to enable warnings or errors for such undefined macro.
Could you let me know if it is possible to enable the warnings or
errors for this case?

$(eval $(call nothing, 1))

-- 
Regards,
Peng