I'm having a problem with using C macros and was wondering if anybody could help.

I trying to replace callee function using C macro or remove parenthesis of function call. The callee function is passed to macro in form of function call.

I want to transform code to like this:

SOME_MACRO(any_function1(param0, param1))  ->  myfunc(param0, param1)
SOME_MACRO(any_function2(param0, param1, param2))  ->  myfunc(param0, param1, param2)

Is it possible?

Any help would be appreciated.

CodePudding user response：

You can't write a macro like SOME_MACRO(any_function(param0, param1)) because the contents would be regarded as one single preprocessor token and you wouldn't be able to grab the any_function part of it.

Instead simply do #define any_function other_function.

More advanced topic: in case you need to change parameters or add type safety etc, create a "wrapper macro". Take for example this artificial macro:

#define any_function(x, y) _Generic((x), int: other_function) (x,y,z)

This example does 3 things:

• Replace calls to any_function with other_function
• Enforce a stricter type safety on the first argument than what's required by a simple function call. For example if you require that the x argument must be int and not unsigned int, long, short or similar, which would otherwise be fine to pass to a function taking int as parameter ("lvalue conversion" would occur).
• Add a 3rd parameter z to the call, not present in the caller code, for compatibility reasons. Similarly, we could as well drop one of the parameters or change the order of them.