No mixin inside asm blocks

[Ali Çehreli]

On 01/30/2013 11:08 AM, Philippe Sigaud wrote:
 > On Wed, Jan 30, 2013 at 4:01 PM, Ali Çehreli<acehreli at yahoo.com>  wrote:
 >> A friend of mine is trying to figure out the D equivalent of using 
macros
 >> with asm blocks in C:
 >>
 >> #define NEXT() __asm__("jmp *%0"::"r"((++ip)->jmp)); goto *ip->jmp
 >>
 >> D's asm blocks are very restrictive: mixins are not allowed. What do 
you do
 >> in D?
 >
 > Is it possible to enclose an asm statement into a mixin?
 >
 > mixin("
 > asm {
 >
 > ....
 >
 > code to include
 >
 > }");

Thanks!

It is almost there, except that one needs to use a compile-time "macro 
expansion" solution, which I am too lazy to try now. :) I am confident 
that the following program will work after doing that. (Of course also 
after replacing 'writeln' with 'mixin'.)

import std.stdio;
import std.regex;

string expandNexts(string input)
{
     enum e = ctRegex!("Next;", "g");
     // NOTE: This is an example. Of course, the second string below 
should be
     // whatever the "macro" should be expanded as.
     return replace(input, e, "cmp EAX,0;");
}

void main()
{
     writeln (expandNexts(q{
         asm
         {
             mov EAX, 10000;
             Next;
             Next;
             Next;
             Next;
             Next;
         }
     }));
}

The program prints

         asm
         {
             mov EAX, 10000;
             cmp EAX,0;
             cmp EAX,0;
             cmp EAX,0;
             cmp EAX,0;
             cmp EAX,0;
         }

Ali