Register calling convention for asm functions...

[Daniel Keep]

Chris Warwick Wrote:

> What do i need to do to get register calling convention for asm? I've found 
> extern(C) for cdecl calling convention, and i have seen mention of the 
> 'naked' keyword but cant work out where it goes... im not even sure if it 
> does cause register calling convention or just causes the compiler to omit 
> entry and exit code.
> 
> I assume it must be possible to write asm functions that take arguments in 
> the eax,ecx,edx registers?
> 
> thanks,
> 
> cw 

You put 'naked' at the top of a function body, and it causes the compiler to omit the function prelude and prologue.  So, for example:

void breakpoint()
{
    naked;
    asm { int 3; }
}

Compiles literally as

  INT 0x3

As for arguments in registers, you can't do that.  If you want to have a function that you pass arguments to via registers, then you need to "call" it using asm.

I'd write you an example, but I'm typing this from a Mac at uni and, well, my assembler ain't that crash-hot :3

        -- Daniel