prolog and epilog code

[Steven Schveighoffer via Digitalmars-d-learn]

On 8/2/16 1:04 PM, Rufus Smith wrote:
> On Tuesday, 2 August 2016 at 16:30:08 UTC, Adam D. Ruppe wrote:
>> On Tuesday, 2 August 2016 at 16:21:07 UTC, Rufus Smith wrote:
>>> How does one use C main? extern C?
>>
>> extern(C) int main()
>>
>> should do it
>
> It doesn't seem to be that easy!
>
> https://wiki.dlang.org/Runtime_internals

This is just explaining how the runtime currently works, not how you 
should override it.

It's really easy actually. Example:

$ cat main.c
#include <stdio.h>

extern int rt_init();
extern void d_func();
int main(int argc, char *argv[])
{
     printf("hello from C!\n");
     rt_init();
     printf("done initializing runtime\n");
     d_func();
}
$ cat dmain.d
extern(C) void d_func()
{
     import std.stdio;
     writeln("hello from D!");
}

shared static this()
{
     import std.stdio;
     writeln("doing some pre-run init!");
}
$ gcc -c main.c
$ dmd dmain.d main.o
$ ./dmain
hello from C!
doing some pre-run init!
done initializing runtime
hello from D!

-Steve