Re: A guide on setting up C/C++ development environment for Emacs

[solidius4747@gmail.com]

Vào 21:39:59 UTC+7 Thứ tư, ngày 27 tháng tám năm 2014, Thien-Thi Nguyen đã viết:
> () Tu Hoang Do <solidius4747@gmail.com>
> 
> () Wed, 27 Aug 2014 20:18:27 +0700
> 
> 
> 
>    CEDET is not slow.
> 
> 
> 
> Maybe it's time someone implemented a MEEPS
> 
> (Millions of Emacs Evaluations Per Second) counter.
> 
> Then, we can qualify that statement w/ "on a N MEEPS"
> 
> system and people on old M MEEPS (M<<N) computers can
> 
> snort w/ wonder...  :-D
> 
> 
> 
> -- 
> 
> Thien-Thi Nguyen
> 
>    GPG key: 4C807502
> 
>    (if you're human and you know it)
> 
>       read my lisp: (responsep (questions 'technical)
> 
>                                (not (via 'mailing-list)))
> 
>                      => nil

Because real parsing takes time and such a task, while possible using Emacs Lisp, but is too much for current Emacs implementation. CEDET does some nice optimizations to speed it up as fast as it can: idle parsing, caching and incremental parsing to reduce computational time. Consider someone using Clang to generate tag database: https://github.com/drothlis/clang-ctags#performance:

"Running clang-ctags over a much larger input, such as the entire llvm C/C++ sources (7k files, 1.8 million lines of code) took 98 minutes and a peak memory usage of 140MB."

It's just 1.8 million lines of code. And that's Clang. GNU Global only needs a few minutes to generate tag database for Linux kernel, which is more than 14 million lines of code and more than 40k files. Do you say Clang is worse than GNU Global?