[LLVMdev] Dynamic configuration for llvmc2

Anton Korobeynikov anton at korobeynikov.info
Mon Nov 17 17:02:26 PST 2008


Hello, Patrick

>> As Anton said, that was intentional. We wanted to minimize the number
>> of dependencies and keep the driver lean and mean.
>
> Definitely a good idea, which is why I wouldn't suggest Python or Perl :)
> For my plugin I would probably just add the Lua VM into the tree, so that
> there wouldn't be a dependency at all. It's under a compatible MIT/X11
> license and is only 17k lines of ANSI C that should add around 150k to the
> driver. For me the driver is about 350k, so that would mean a driver around
> 500k, which doesn't seem that big of a difference.
Honestly speaking, size does not matter much. We do care about speed,
that's why we always prefer to generated sources to some scripting
languages. Consider pretty typical situations, when compiler is
invoked on bunch of small files at -O0 level, or during generation of
PCH. In such situations the overhead of compiler driver is pretty
visible and having extra VM will lead to funny situation, when pure
compiler driver time will dominate over compilation time itself.

If you don't care about such things - go ahead and think about sane
design proposal, how one can hook any extra scripting language for
llvmc2 without slowdown of 'main path'. This surely will be accepted!
-- 
With best regards, Anton Korobeynikov
Faculty of Mathematics and Mechanics, Saint Petersburg State University



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