On 5/22/2015 10:26 PM, Suliman wrote:
Really hard to understand...
So what what would call at first ?
extern(C) int main()
or
int _Dmain()
Your D programs have multiple layers. There is the C runtime, DRuntime,
and your program code.
The C runtime is at the bottom. When the program launches, it gets
control first. When it has done its work, it looks for a main function
and calls it. Normally, in a C program, that would be the main function
that you implement. But in D, it is a function implemented by DRuntime.
The DRuntime main, because it is called by C, must be declared as
extern(C) in order for the C runtime to recognize it. When it is called
by the C runtime, then DRuntime does some housekeeping work (calling
module constructors, intializing the garbage collecter, and so on). When
it is done with that, it then calls the main function that you
implemented in your program.
The exception to this is when a program is compiled on Windows with
WinMain enabled. In this case, the C main is not the entry point, but
WinMain is instead. DRuntime does not implement WinMain, so when
compiling a D program like this, we have to call initialize DRuntime
manually.
