[cfe-dev] Announcing Crange

[Anurag]

Hello Tobias,

On Fri, May 9, 2014 at 8:06 PM, Tobias Grosser <tobias at grosser.es> wrote:
> As Renato said, the run-time is critical. Some people may suggest to
> implement this in C/C++. However, starting with python is probably a good
> choice to try this out and also to understand the performance implications.

Implementing this in python did turn out to be a good learning
experience. I wouldn't have come this far, had I decided to stick to
C++.

> Some ideas:
>
>         - You may want to look at the compilation database support in
>           libclang to retrieve the set of files to process as well as
>           the corresponding command lines

Compilation database support is on the top of my 'must have' list. To
keep things simple for now, I merely search for all C/C++ source and
header files and parse them, thereby losing command line includes and
flags.

>         - I wonder how quick querying the database is. In fact,
>           if those queries are quick (less than 50ms) even for big
>           databases, this would extremely interesting as you could in
>           an editor for example add missing includes as you type.

Identifier looks are quite fast. For the 22GB tags database I tested
earlier, I usually get ~60ms times. For references lookup I think I've
got bad SQL, since its taking a few seconds to respond.


> Ah, and it does actually only work if I don't use this worker stuff, but
> apply this patch:
>
> -        pool.map(worker, worker_params)
> +
> +        for p in worker_params:
> +            worker(p)

Ah, It seems like there's a bug in my code. It doesn't spawn the
multiprocessing pool in some cases. I'll have a close look at this.

Thanks for your feedback Tobias

Anurag