Compiler complaining of undeclared variable in a macro

Question

I am using a macro defined in the same source file as:

#define MY_MACRO (a, b,...) (...)

The macro is being used later in the file.

However, the compiler complains:

error: a undeclared (first use in this function).

It's really weird.. am I missing something obvious?

Answer 1

I think the problem is that there is a SPACE between MY_MACRO and (a, b, ...). It should be like this:

#define MY_MACRO(a, b,...) (...)

Answer 2

Remove the space between the macro name and the argument list. The space separates the macro head from the body, so it is being treated as a macro with no arguments that expands into the desired argument list followed by the desired body.