I'd like to do some stuffs before main function. I have multiple source files. In each file, there is some work that needs to be done before main. It was no problem in C++, but problematic with C.

In C++, this can be done by two ways:

1. Exploiting a constructor of a global class/struct.
2. Calling a function to a global variable

For example, static const int __register_dummy_ = __AddRegisterMetaInfo(...);

However, in C, either ways is impossible. Obviously, there is no constructor. So, the first option is inherently impossible.

I thought that the second option would be possible, but not compiled in C (I tested only with Visual C++. It gives C2099.). C only allows a constant to a non-automatic variable.

Is there any way to call some functions before main?