Implicitly pass arguments

Question

I'm working on a custom unit-testing framework that doesn't display the filename/line numbers of failed tests. I know I could require them as arguments for the report_results function but that seems like a lot of text.

Is there a way to make it so that __FILE__ and __LINE__ are always passed with the function, even if I don't pass them when I call it?

You can do something like this in C++:

void func(char *file=__FILE__, int line=__LINE__)(int more_args) {}

Answer 1

use a macro in your code, to call an underlying function

#define func(arg) real_func(__FILE__,__LINE__,arg)

where real_func is

void real_func(const char *file, int line, int arg);

In your code, when you call func(12), it expands to a call to real_func, with actual file path and line of the call. You can even support variable argument functions in C99 with variadic macros as a frontend.