How about a 100% CTFE?

[Don]

On 07.11.2011 14:13, Gor Gyolchanyan wrote:
> After reading
>
>      http://prowiki.org/wiki4d/wiki.cgi?DMDSourceGuide
>      https://github.com/gor-f-gyolchanyan/dmd/blob/master/src/interpret.c
>
> I had a thought:
> Why not compile and run CTFE code in a separate executable, write it's
> output into a file, read that file and include it's contents into the
> object file being compiled?
> This would cover 100% of D in CTFE, including external function calls
> and classes;
> String mixins would simply repeat the process of compiling and running
> an extra temporary executable.
>
> This would open up immense opportunities for such things as
> library-based build systems and tons of unprecedented stuff, that I
> can't imagine ATM.

First comment: classes and exceptions now work in dmd git. The remaining 
limitations on CTFE are intentional.

With what you propose:
Cross compilation is a _big_ problem. It is not always true that the 
source CPU is the same as the target CPU. The most trivial example, 
which applies already for DMD 64bit, is size_t.sizeof. Conditional 
compilation can magnify these differences. Different CPUs don't just 
need different backend code generation; they may be quite different in 
the semantic pass. I'm not sure that this is solvable.

version(ARM)
{
    immutable X = armSpecificCode(); // you want to run this on an X86???
}